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/CI.yml

@@ -21,7 +21,7 @@ jobs:
         arch:
           - x64
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: julia-actions/setup-julia@latest
         with:
           version: ${{ matrix.version }}

.github/workflows/docs.yml

@@ -10,7 +10,7 @@ jobs:
      name: Build Documentation
      runs-on: ubuntu-latest
      steps:
-       - uses: actions/checkout@v4
+       - uses: actions/checkout@v5
        - uses: julia-actions/setup-julia@v2
          with:
            version: '1'