enable validation in branch 5.x.x (#1377)

Author: Lokowandtg

.github/workflows/ci-java.yml

@@ -4,9 +4,11 @@ on:
   push:
     branches:
       - main
+      - 5.x.x
   pull_request:
     branches:
       - main
+      - 5.x.x
 
 jobs:
   build: