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/main.yml

@@ -8,7 +8,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout the repository.
-       uses: actions/checkout@v3
+       uses: actions/checkout@v4
      - name: Download php-binaries.
        run: "curl -sL https://github.com/pmmp/PHP-Binaries/releases/latest/download/PHP-Linux-x86_64-PM5.tar.gz -o php.tar.gz"
      - name: Extract php-binaries.