Added JDK 21 for testing

Author: alex268

.github/workflows/build.yaml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        java: [ '8', '11', '17']
+        java: [ '8', '11', '17', '21']
 
     env:
         MAVEN_ARGS: --batch-mode --update-snapshots -Dstyle.color=always -DYDB_DOCKER_ISOLATION=true

.github/workflows/ci.yaml

@@ -75,7 +75,7 @@ jobs:
 
     strategy:
       matrix:
-        java: [ '8', '11', '17']
+        java: [ '8', '11', '17', '21']
 
     env:
         MAVEN_ARGS: --batch-mode -Dstyle.color=always -DYDB_DOCKER_ISOLATION=true