Changed ci.yml to use JDK 11.

Author: cheeseng

.github/workflows/ci.yml

@@ -12,6 +12,6 @@ jobs:
       uses: actions/setup-java@v3
       with:
         distribution: temurin
-        java-version: 8
+        java-version: 11
     - name: Build and Test
       run: sbt -v +test