Update CI Test Action (Cache key)

Author: robotgryphon

.github/workflows/ci-tests.yml

@@ -44,7 +44,7 @@ jobs:
         uses: actions/cache@v2
         with:
           path: ~/.gradle/caches
-          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}
+          key: ${{ runner.os }}-gradle
           restore-keys: ${{ runner.os }}-gradle
 
       - name: Grant execute permission for gradlew