Simplify staging workflow by removing post-process step for branch checkout

Author: frequency403

.github/workflows/staging.yml

@@ -68,7 +68,4 @@ jobs:
           commit_username: ${{ github.repository_owner }}
           commit_email: ${{ github.repository_owner }}@users.noreply.github.com
           ssh_private_key: ${{ secrets.AUR_SSH_PRIVATE_KEY }}
-          commit_message: "Development update ${{ needs.prepare.outputs.tag }}"
-          post_process: |
-            git fetch origin master
-            git checkout master || git checkout -b master origin/master
+          commit_message: "Development update ${{ needs.prepare.outputs.tag }}"