Bump actions/checkout from 3 to 4 (#24)

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

.github/workflows/dependabot.yml

@@ -8,7 +8,7 @@ jobs:
     env:
       GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: checkout PR branch
         # set upstream for other gh commands
         run: gh pr checkout ${{github.event.pull_request.number}}

.github/workflows/ruby.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: clone ${{ github.repository }}
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: setup Ruby ${{ matrix.ruby-version }}
         uses: ruby/setup-ruby@v1
         with: