Content Update Workflow: Only run on the main WordPress repo, cleanup…

… the branch after merge, and use a easy to recognise branch name.

.github/workflows/content-update.yml

@@ -11,6 +11,7 @@ permissions:
 
 jobs:
   content-update:
+    if: github.repository_owner == 'WordPress'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
@@ -32,6 +33,8 @@ jobs:
       - name: Create Pull Request
         uses: peter-evans/create-pull-request@v6
         with:
+          branch: automated/content-update
+          delete-branch: true
           add-paths: source/wp-content/themes/wporg-main-2022/**/*.php
           title: 'Content updates from Page Editor'
           commit-message: '[automated] Sync content from Page Editor.'