Bump actions/checkout from 5 to 6

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] <support@github.com>

Author: dependabot[bot]

.github/workflows/dzil-build-and-test.yml

@@ -17,7 +17,7 @@ jobs:
     container:
       image: perldocker/perl-tester:5.40
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run Tests
         env:
           AUTHOR_TESTING: 1
@@ -36,7 +36,7 @@ jobs:
     container:
       image: perldocker/perl-tester:5.40
     steps:
-      - uses: actions/checkout@v5 # codecov wants to be inside a Git repository
+      - uses: actions/checkout@v6 # codecov wants to be inside a Git repository
       - uses: actions/download-artifact@v6
         with:
           name: build_dir