chore(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](https://github.com/actions/cache/compare/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>

.github/workflows/tests.yml

@@ -57,7 +57,7 @@ jobs:
         key: ${{ runner.os }}-${{ env.extensions-cache-key }}
 
     - name: Cache extensions
-      uses: actions/cache@v5
+      uses: actions/cache@v6
       with:
         path: ${{ steps.extcache.outputs.dir }}
         key: ${{ steps.extcache.outputs.key }}
@@ -93,7 +93,7 @@ jobs:
       shell: bash
 
     - name: Cache dependencies
-      uses: actions/cache@v5
+      uses: actions/cache@v6
       with:
         path: "${{ steps.composer-cache.outputs.dir }}"
         key: "${{ runner.os }}-composer-${{ steps.get-date.outputs.date }}-${{ hashFiles('**/composer.json') }}"
@@ -147,7 +147,7 @@ jobs:
         key: ${{ runner.os }}-${{ env.extensions-cache-key }}
 
     - name: Cache extensions
-      uses: actions/cache@v5
+      uses: actions/cache@v6
       with:
         path: ${{ steps.extcache.outputs.dir }}
         key: ${{ steps.extcache.outputs.key }}
@@ -183,7 +183,7 @@ jobs:
       shell: bash
 
     - name: Cache dependencies
-      uses: actions/cache@v5
+      uses: actions/cache@v6
       with:
         path: "${{ steps.composer-cache.outputs.dir }}"
         key: "${{ runner.os }}-composer-${{ steps.get-date.outputs.date }}-${{ hashFiles('**/composer.json') }}"