Update update-changelog.yml

use default branch as reference

Author: herpaderpaldent

.github/workflows/update-changelog.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v3
         with:
-          ref: main
+          ref: ${{ github.event.repository.default_branch }}
 
       - name: Update Changelog
         uses: stefanzweifel/changelog-updater-action@v1
@@ -26,6 +26,6 @@ jobs:
       - name: Commit updated CHANGELOG
         uses: stefanzweifel/git-auto-commit-action@v4
         with:
-          branch: main
+          branch: ${{ github.event.repository.default_branch }}
           commit_message: Update CHANGELOG
           file_pattern: CHANGELOG.md