use_pkgdown_github_pages permissions issue #2279
Description
I realize this is really an issue with GitHub and not with pkgdown itself, but it has prevented me from publishing on GitHub Pages, but I have been unable to find documentation to resolve it, and I'm hoping someone here can help, and possibly add documentation to pkgdown on this topic.
I used usethis::use_pkgdown_github_pages to set up publishing on GitHub pages. When I push a commit to GitHub (no problem with that) it triggers the action to deploy and build the site as expected. The site appears to build successfully, but deployment fails because of a write-access issue. That seems inconsistent with being able to push, so clearly there's something I'm not understanding. The relevant section of the build/deploy log follows. I would greatly appreciate any advice and would gladly write up the solution to go somewhere in pkgdown's documentation if that would be appropriate.
Switched to a new branch 'github-pages-deploy-action/yg1mydceg'
/usr/bin/git commit -m Deploying to gh-pages from @ gregorypenn/BetaBayes@214677f2a17201f8004e29144b58f8613a73e0b0 🚀 --quiet --no-verify
Force-pushing changes...
/usr/bin/git push --force ***github.com/gregorypenn/BetaBayes.git github-pages-deploy-action/yg1mydceg:gh-pages
remote: Write access to repository not granted.
fatal: unable to access 'https://github.com/gregorypenn/BetaBayes.git/': The requested URL returned error: 403
Running post deployment cleanup jobs… 🗑️
/usr/bin/git checkout -B github-pages-deploy-action/yg1mydceg
Reset branch 'github-pages-deploy-action/yg1mydceg'
/usr/bin/chmod -R +rw github-pages-deploy-action-temp-deployment-folder
/usr/bin/git worktree remove github-pages-deploy-action-temp-deployment-folder --force
Error: The deploy step encountered an error: The process '/usr/bin/git' failed with exit code 128 ❌
Notice: Deployment failed! ❌