Use main as the latest version of cpina/github-action-push-to-another-repository@main

Author: mmcky

.github/workflows/publish.yml

@@ -89,7 +89,7 @@ jobs:
           cp lectures/Manifest.toml _build/lecture-julia.notebooks
           ls -a _build/lecture-julia.notebooks
       - name: Commit latest notebooks to lecture-julia.notebooks
-        uses: cpina/github-action-push-to-another-repository@v1.4.1
+        uses: cpina/github-action-push-to-another-repository@main
         env:
           API_TOKEN_GITHUB: ${{ secrets.QUANTECON_SERVICES_PAT }}
         with: