Add setup-gradle action so it can take care of the caching

Author: filiphr

.github/workflows/main.yml

@@ -25,6 +25,8 @@ jobs:
         with:
           distribution: 'zulu'
           java-version: ${{ matrix.version.jdk }}
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v4
       - name: 'Test'
         run: ./gradlew --warning-mode=all build
       - name: 'Generate coverage report'