feat: hibernate 6 add java 21

Author: KirillKurdyukov

.github/workflows/ci-hibernate-dialect.yaml

@@ -20,7 +20,7 @@ jobs:
 
     strategy:
       matrix:
-        java: [ '17' ]
+        java: [ '17', '21' ]
 
     steps:
       - uses: actions/checkout@v4