🩹 [Patch]: Bump PSModule/Invoke-Pester to v5.1.0 (#122)

Bumps the internal `PSModule/Invoke-Pester` action from v4.2.6 to
v5.1.0, keeping this action's public `Version` and `Prerelease` inputs
behaving exactly as documented.

## Changed: Invoke-Pester upgraded to v5.1.0

Invoke-Pester v5.0.0 is a major release that repurposed its `Version`
and `Prerelease` inputs to select the **Pester** module version (NuGet
range syntax) and renamed the GitHub bootstrap-module controls to
`GitHubVersion` and `GitHubPrerelease`.

This action's own `Version` and `Prerelease` inputs — documented as
selecting the GitHub module version — are now wired to Invoke-Pester's
`GitHubVersion` and `GitHubPrerelease`, so their behavior is unchanged
for consumers. This action's public interface is unaffected.

## Technical Details

- `action.yml`: bumped the pinned `PSModule/Invoke-Pester` reference to
`4ff3319` (v5.1.0).
- Remapped the Invoke-Pester step's `Version` → `GitHubVersion` and
`Prerelease` → `GitHubPrerelease` to preserve the meaning of this
action's inputs across the v5.0.0 breaking change.
- The `Get test paths` step is a plain PowerShell step and does not
consume these inputs, so no other change is needed.
- Pester version selection is left at the v5 default (latest).
- Mirrors the same change in PSModule/Invoke-ScriptAnalyzer#32.

Invoke-Pester v5.0.0 release notes:
https://github.com/PSModule/Invoke-Pester/releases/tag/v5.0.0

Author: MariusStorhaug

action.yml

@@ -281,16 +281,16 @@ runs:
         ${{ github.action_path }}/src/main.ps1
 
     - name: Invoke-Pester
-      uses: PSModule/Invoke-Pester@9cf262a79e7528d5af41c875c35dae91c44d18dd # v4.2.6
+      uses: PSModule/Invoke-Pester@4ff33199141fdf22568990b6107fe3148ae93a1c # v5.1.0
       id: test
       env:
         LocalTestPath: ${{ steps.paths.outputs.LocalTestPath }}
         WorkingDirectory: ${{ inputs.WorkingDirectory }}
       with:
         Debug: ${{ inputs.Debug }}
         Verbose: ${{ inputs.Verbose }}
-        Version: ${{ inputs.Version }}
-        Prerelease: ${{ inputs.Prerelease }}
+        GitHubVersion: ${{ inputs.Version }}
+        GitHubPrerelease: ${{ inputs.Prerelease }}
         WorkingDirectory: ${{ inputs.WorkingDirectory }}
         Path: ${{ steps.paths.outputs.TestPath }}
         StepSummary_Mode: ${{ inputs.StepSummary_Mode }}