update ci

Author: CarGuo

.github/workflows/ci.yml

@@ -44,7 +44,7 @@ jobs:
         uses: actions/setup-java@v2
         with:
           distribution: 'zulu'
-          java-version: 8
+          java-version: 11
       - uses: subosito/flutter-action@v1
         with:
           flutter-version: '3.0.0'