CI: Use JDK 8 for older Jersey versions

Author: deki

.github/workflows/continuous-integration-workflow.yml

@@ -22,6 +22,10 @@ jobs:
       - uses: actions/checkout@v2
       - name: Build latest
         run: ./gha_build.sh jersey true true
+      - name: Set up JDK 8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 8
       - name: Build Jersey 2.27
         run: ./gha_build.sh jersey false false -Djersey.version=2.27
       - name: Build Jersey 2.28