Bump actions/checkout from 4.2.2 to 5.0.0 (#277)

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.2.2 to 5.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@11bd719...08c6903)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 5.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ${{ matrix.runs-on }}
     steps:
       - name: Checkout code
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
 
       - name: Install GFortran (macOS)
         if: matrix.os == 'macos'

.github/workflows/cmake.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout code
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
 
       - name: Check if all exercise cmake files are up to date
         run: ./bin/check-cmake-files-up-to-date