Runner v2.333.0 breaks `case` function

**Describe the bug**

The GitHub runner version 2.333.0 reports an error when the `case` function is used for default values in composite actions. The error message is `Unrecognized function: 'case'`. This error occurs only for 2.333.0, in 2.332.0 the same actions work without issues.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a composite action that uses the `case` function in the default value for an input. For example
   ```yaml
   name: Test Action

   inputs:
     test:
       default: ${{ case(github.event_name == 'push', 'bar', 'baz') }}
       description: "This input uses `case` in its default value."

   runs:
     using: composite
     steps:
       - shell: bash
         run: ":"
   ```
2. Create a workflow that uses the action without supplying a value for the `test` input:
   ```yaml
   on: push

   jobs:
     create:
       runs-on: ubuntu-slim
       steps:
         - uses: actions/checkout@v6
         - uses: ./my-action
   ```
3. See that the workflow fails to call `./my-action` with an error message of `Unrecognized function: 'case'`.

**Expected behavior**

I expect the action to be called successfully. In the example case I expect the `default` value of the `test` input to evaluate to `'bar'`.

## Runner Version and Platform
Version of your runner?
2.333.0

OS of the machine running the runner? OSX/Windows/Linux/...
```
- OS: Linux (x64)
- Source: Docker
- Name: ubuntu:24.04
- Version: 20260323.53.1
```

The example is running on GitHub-hosted runners.

## What's not working?

The full error message is
```
Error: The template is not valid. /home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14): Unrecognized function: 'case'. Located at position 1 within expression: case(github.event_name == 'push', 'bar', 'baz')
```

I have created a repository for reproduction at https://github.com/codello/broken-case-function. An example run of the workflow above (including the error) can be found at https://github.com/codello/broken-case-function/actions/runs/23610377699/job/68764200008

## Job Log Output

<details>
<summary>Debug log output of the step</summary>

```
##[debug]Evaluating condition for step: 'Run ./my-action'
##[debug]Evaluating: success()
##[debug]Evaluating success:
##[debug]=> true
##[debug]Result: true
##[debug]Starting: Run ./my-action
Prepare all required actions
##[debug]Loading inputs
##[debug]/home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14):
Error: The template is not valid. /home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14): Unrecognized function: 'case'. Located at position 1 within expression: case(github.event_name == 'push', 'bar', 'baz')
##[debug]GitHub.DistributedTask.ObjectTemplating.TemplateValidationException: The template is not valid. /home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14): Unrecognized function: 'case'. Located at position 1 within expression: case(github.event_name == 'push', 'bar', 'baz')
##[debug]   at GitHub.DistributedTask.ObjectTemplating.TemplateValidationErrors.Check()
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerLegacy.EvaluateDefaultInput(IExecutionContext executionContext, String inputName, TemplateToken token)
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerWrapper.<>c__DisplayClass7_0.<EvaluateDefaultInput>b__0()
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerWrapper.EvaluateAndCompare[TLegacy,TNew](IExecutionContext context, String methodName, Func`1 legacyEvaluator, Func`1 newEvaluator, Func`3 resultComparer)
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerWrapper.EvaluateDefaultInput(IExecutionContext executionContext, String inputName, TemplateToken token)
##[debug]   at GitHub.Runner.Worker.ActionRunner.RunAsync()
##[debug]   at GitHub.Runner.Worker.StepsRunner.RunStepAsync(IStep step, CancellationToken jobCancellationToken)
##[debug]Finishing: Run ./my-action
```

</details>

**Describe the bug**

The GitHub runner version 2.333.0 reports an error when the `case` function is used for default values in composite actions. The error message is `Unrecognized function: 'case'`. This error occurs only for 2.333.0, in 2.332.0 the same actions work without issues.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a composite action that uses the `case` function in the default value for an input. For example
   ```yaml
   name: Test Action

   inputs:
     test:
       default: ${{ case(github.event_name == 'push', 'bar', 'baz') }}
       description: "This input uses `case` in its default value."

   runs:
     using: composite
     steps:
       - shell: bash
         run: ":"
   ```
2. Create a workflow that uses the action without supplying a value for the `test` input:
   ```yaml
   on: push

   jobs:
     create:
       runs-on: ubuntu-slim
       steps:
         - uses: actions/checkout@v6
         - uses: ./my-action
   ```
3. See that the workflow fails to call `./my-action` with an error message of `Unrecognized function: 'case'`.

**Expected behavior**

I expect the action to be called successfully. In the example case I expect the `default` value of the `test` input to evaluate to `'bar'`.

## Runner Version and Platform
Version of your runner?
2.333.0

OS of the machine running the runner? OSX/Windows/Linux/...
```
- OS: Linux (x64)
- Source: Docker
- Name: ubuntu:24.04
- Version: 20260323.53.1
```

The example is running on GitHub-hosted runners.

## What's not working?

The full error message is
```
Error: The template is not valid. /home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14): Unrecognized function: 'case'. Located at position 1 within expression: case(github.event_name == 'push', 'bar', 'baz')
```

I have created a repository for reproduction at https://github.com/codello/broken-case-function. An example run of the workflow above (including the error) can be found at https://github.com/codello/broken-case-function/actions/runs/23610377699/job/68764200008

## Job Log Output

<details>
<summary>Debug log output of the step</summary>

```
##[debug]Evaluating condition for step: 'Run ./my-action'
##[debug]Evaluating: success()
##[debug]Evaluating success:
##[debug]=> true
##[debug]Result: true
##[debug]Starting: Run ./my-action
Prepare all required actions
##[debug]Loading inputs
##[debug]/home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14):
Error: The template is not valid. /home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14): Unrecognized function: 'case'. Located at position 1 within expression: case(github.event_name == 'push', 'bar', 'baz')
##[debug]GitHub.DistributedTask.ObjectTemplating.TemplateValidationException: The template is not valid. /home/runner/work/broken-case-function/broken-case-function/./my-action/action.yml (Line: 5, Col: 14): Unrecognized function: 'case'. Located at position 1 within expression: case(github.event_name == 'push', 'bar', 'baz')
##[debug]   at GitHub.DistributedTask.ObjectTemplating.TemplateValidationErrors.Check()
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerLegacy.EvaluateDefaultInput(IExecutionContext executionContext, String inputName, TemplateToken token)
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerWrapper.<>c__DisplayClass7_0.<EvaluateDefaultInput>b__0()
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerWrapper.EvaluateAndCompare[TLegacy,TNew](IExecutionContext context, String methodName, Func`1 legacyEvaluator, Func`1 newEvaluator, Func`3 resultComparer)
##[debug]   at GitHub.Runner.Worker.ActionManifestManagerWrapper.EvaluateDefaultInput(IExecutionContext executionContext, String inputName, TemplateToken token)
##[debug]   at GitHub.Runner.Worker.ActionRunner.RunAsync()
##[debug]   at GitHub.Runner.Worker.StepsRunner.RunStepAsync(IStep step, CancellationToken jobCancellationToken)
##[debug]Finishing: Run ./my-action
```

</details>

## Runner and Worker's Diagnostic Logs

Here is the log archive from GitHub Actions: [logs_62197128874.zip](https://github.com/user-attachments/files/26286002/logs_62197128874.zip)

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Runner v2.333.0 breaks `case` function #4315

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Runner v2.333.0 breaks case function #4315

Description

Runner Version and Platform

What's not working?

Job Log Output

Runner Version and Platform

What's not working?

Job Log Output

Runner and Worker's Diagnostic Logs

Metadata

Metadata

Assignees

Labels

Type

Fields

Projects

Milestone

Relationships

Development

Issue actions

Runner v2.333.0 breaks `case` function #4315