fix triggering for "Validate Gradle Wrapper" pipeline (#24181)

### Description

currently it is triggered on every branch.

Author: fs-eire

.github/workflows/gradle-wrapper-validation.yml

@@ -3,7 +3,11 @@
 # This workflow was copied from the link above.
 
 name: "Validate Gradle Wrapper"
-on: [push, pull_request]
+on:
+  push:
+    branches: [ main, 'rel-*']
+  pull_request:
+    branches: [ main, 'rel-*']
 
 jobs:
   validation: