ci: Fix yaml (#7038)

Oops, nested the `pull_request` inside of the `push`!

Author: mydea

.github/workflows/gitflow-sync-master.yml

@@ -1,10 +1,9 @@
 name: Gitflow - Sync develop into master
 on:
-  push:
-    pull_request:
-      - types: [closed]
-      - branches:
-          - 'develop'
+  pull_request:
+    - types: [closed]
+    - branches:
+        - 'develop'
 
 env:
   MAIN_BRANCH: master