Bump actions/checkout from 2.4.0 to 3

Bumps [actions/checkout](https://github.com/actions/checkout) from 2.4.0 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2.4.0...v3)

---
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/matrix.yml

@@ -11,6 +11,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: ⤵️ Check out configuration from GitHub
-        uses: actions/checkout@v2.4.0
+        uses: actions/checkout@v3
       - name: 🚀 Run yamllint
         uses: frenck/action-yamllint@v1.1.2