Update publish_sparkle.yml

.github/workflows/publish_sparkle.yml

@@ -45,6 +45,7 @@ jobs:
         run: |
           git config --global user.name "github-actions[bot]"
           git config --global user.email "github-actions[bot]@users.noreply.github.com"
+          git checkout main
           git add appcast.xml
           git add lo-rain.dmg
           git commit -m "Update appcast.xml and lo-rain.dmg for release ${{ github.event.release.tag_name }}"