Modify pull request branches in maven.yml

Updated the branches for pull request triggers in the Maven workflow.

Signed-off-by: Ryan Baxter <ryan.baxter@broadcom.com>

Author: ryanjbaxter

.github/workflows/maven.yml

@@ -4,10 +4,8 @@
 name: Build
 
 on:
-  push:
-    branches: [ main, 4.3.x, 4.2.x, 4.1.x ]
   pull_request:
-    branches: [ main, 4.3.x, 4.2.x, 4.1.x ]
+    branches: [ main, 4.3.x ]
 
 jobs:
   build:
@@ -39,4 +37,4 @@ jobs:
       uses: actions/upload-artifact@v7
       with:
         name: surefire-reports
-        path: '**/surefire-reports/*'
+        path: '**/surefire-reports/*'