Fixed setup java error

migration guide: https://github.com/actions/setup-java/blob/main/docs/switching-to-v2.md

Seems like the java version should be put as 11 instead of 1.11

.github/workflows/gradle.yml

@@ -13,6 +13,6 @@ jobs:
       uses: actions/setup-java@v2
       with:
         distribution: temurin
-        java-version: 1.11
+        java-version: 11
     - name: Build with Gradle
       run: ./gradlew build