ci(deps): update actions/cache action to v4 (#292)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/example-app.yml

@@ -36,7 +36,7 @@ jobs:
           cache-key: ${{ runner.os }}-flutter-${{ steps.fvm-config.outputs.FLUTTER_VERSION }}-${{ hashFiles('**/pubspec.lock') }}
 
       - name: Cache Pub 💾
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: |
             ${{ steps.setup-flutter.outputs.CACHE-PATH }}