Using TCK Tested JDK builds of OpenJDK

The AdoptOpenJDK has been discontinued since July 2021. When using Zulu you get all the latest updated (TCK Tested) builds for all versions of OpenJDK included archived major fixed versions.

.github/workflows/test-pr.yml

@@ -15,7 +15,7 @@ jobs:
         uses: actions/setup-java@v2
         with:
           java-version: '8'
-          distribution: 'adopt'
+          distribution: 'zulu'
       - name: Cache m2 package
         uses: actions/cache@v2
         with: