Bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/test.yaml

@@ -25,7 +25,7 @@ jobs:
             git config --global core.autocrlf input
           fi
 
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - uses: ./
         with:

action.yaml

@@ -95,7 +95,7 @@ runs:
       run: git config --global core.autocrlf input
 
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       if: ${{ fromJSON(inputs.checkout) }}
       with:
         # Work around the fact that in the context of a pull request github.sha
@@ -115,7 +115,7 @@ runs:
         echo "short=${SHA:0:7}" >> $GITHUB_OUTPUT
 
     - name: Checkout build variables
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       if: ${{ fromJSON(inputs.checkout-build-variables) }}
       with:
         repository: secondlife/build-variables