Update ant.yml

Updated workflow to build using same version of JDK (11) as local build process

Author: cicirello

.github/workflows/ant.yml

@@ -16,9 +16,9 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 1.8
+    - name: Set up JDK 1.11
       uses: actions/setup-java@v1
       with:
-        java-version: 1.8
+        java-version: 1.11
     - name: Build with Ant
       run: ant -noinput -buildfile build/build.xml