actions/cache@v1 is now deprecated so update to v4

as per this article:

https://github.blog/changelog/2024-12-05-notice-of-upcoming-releases-and-breaking-changes-for-github-actions/#actions-cache-v1-v2-and-actions-toolkit-cache-package-closing-down

Author: leeturner

.github/workflows/gradle.yml

@@ -35,7 +35,7 @@ jobs:
       run: chmod +x gradlew
 
     - name: Cache Gradle packages
-      uses: actions/cache@v1
+      uses: actions/cache@v4
       with:
         path: ~/.gradle/caches
         key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}