Update gradle.yml

Author: ZheSun88

.github/workflows/gradle.yml

@@ -26,7 +26,7 @@ jobs:
           ~/.gradle/wrapper
         key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle.kts', 'gradle/wrapper/gradle-wrapper.properties', 'gradle.properties') }}
     - name: Cache pnpm packages
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: |
           ~/.vaadin