build(deps): bump actions/cache from 5 to 6

Bumps [actions/cache](https://github.com/actions/cache) from 5 to 6.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v5...v6)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/linux.yml

@@ -42,7 +42,7 @@ jobs:
           echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
 
       - name: Init Composer Cache # Docs: <https://git.io/JfAKn#php---composer>
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-composer-${{ matrix.php }}-${{ hashFiles('**/composer.json') }}
@@ -52,7 +52,7 @@ jobs:
         run: cd tests/php_test_files && composer update --prefer-dist --no-progress --ansi
 
       - name: Init Go modules Cache # Docs: <https://git.io/JfAKn#go---modules>
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/go/pkg/mod
           key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}