Update gradle.yml

Author: Foso

.github/workflows/gradle.yml

@@ -12,7 +12,7 @@ jobs:
     - name: Set up JDK 1.8
       uses: actions/setup-java@v3
       with:
-        java-version: 1.8
+        java-version: '8'
         distribution: 'zulu'
     - name: Build with Gradle
       run: ./gradlew clean build