Bump actions/cache from 3 to 4 (#85)

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

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
           tools: composer
       - id: composer-cache
         run: echo "::set-output name=directory::$(composer config cache-dir)"
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
         with:
           path: ${{ steps.composer-cache.outputs.directory }}
           key: ${{ matrix.php }}-composer-${{ hashFiles('**/composer.lock') }}
@@ -74,7 +74,7 @@ jobs:
         run: echo "::set-output name=directory::$(composer config cache-dir)"
 
       - name: Cache composer dependencies
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.composer-cache.outputs.directory }}
           key: ${{ matrix.php }}-composer-${{ hashFiles('**/composer.lock') }}