Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/perltest.yml

@@ -21,7 +21,7 @@ jobs:
         perl: [ 'latest' ]
     name: Perl ${{ matrix.perl }} on ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up perl
         uses: shogo82148/actions-setup-perl@v1
         with:
@@ -36,7 +36,7 @@ jobs:
     container: davorg/perl-coveralls:latest
     name: Test coverage
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: apt-get -y install pandoc
       - name: Install modules
         run: cpanm -n --installdeps .