.github: run Sonar Check only on PRs from apache/cloudstack branches (apache#8058)

This PR fixes apache#8050

(cherry picked from commit 864a195)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: weizhouapache

.github/workflows/sonar-check.yml

@@ -28,7 +28,7 @@ concurrency:
 
 jobs:
   build:
-    if: github.repository == 'apache/cloudstack'
+    if: github.repository == 'apache/cloudstack' && github.event.pull_request.head.repo.full_name == github.repository
     name: Sonar JaCoCo Coverage
     runs-on: ubuntu-22.04
     steps: