Attempting to fix java version support range

Author: PicoCreator

.github/workflows/gradle-build.yml

@@ -15,6 +15,10 @@ jobs:
       uses: actions/setup-java@v1
       with:
         java-version: 1.8
+    - name: Set up JDK 11
+      uses: actions/setup-java@v1
+      with:
+        java-version: 11
     - name: Cache Gradle packages
       uses: actions/cache@v2
       with: