added specified branch

Author: ddevsr

.github/workflows/label-signing.yml

@@ -1,5 +1,11 @@
 name: Check Signed PR
-on: pull_request
+on:
+  pull_request:
+    branches:
+      - 'dev'
+  push:
+    branches:
+      - 'dev'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}