chore(deps): bump actions/checkout from 5 to 6 (#1883)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/test.yml

@@ -37,7 +37,7 @@ jobs:
       with:
         version: ${{ matrix.emacs_version }}
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Install stack and ghc
       run: nix profile install 'nixpkgs#stack' 'nixpkgs#ghc'
     - name: Install texinfo