{find,fix,merge}_outdated_appcasts: prevent non-maintainers from spamming the repo

[jawshooah]

It was an absolutely terrible idea to expose user-facing scripts that automatically generate GitHub issues and PRs for outdated casks. These scripts were always intended to be run only by maintainers, and even then only until we had the means to automate them, but no safeguards were ever put in place to ensure that non-maintainers did not run them and spam the repo with issues.

The recent spate of "outdated cask" issues across this repo, homebrew-versions, and homebrew-fonts have made it clear that we need to either build these safeguards into the scripts, or abandon them completely. As far as I can tell, they haven't been run in months, so I don't think it would be a great loss to remove them, at least until we have a better scheme in place to automatically update casks based on appcast.

@caskroom/maintainers, thoughts?

---

Side note, if you're interested, here's the script I used to remediate this:

outdated_cask_issues=($(
  ghi list --creator Saklad5 --no-labels --no-pulls \
  | grep --ignore-case 'Outdated cask' \
  | awk '{print $1}'
))
printf "Close issues generated by find_outdated_appcasts\n\n" > close_issues_msg
for issue in "${outdated_cask_issues[@]}"; do
  echo "Closes #${issue}" >> close_issues_msg
done
git commit --allow-empty --file close_issues_msg
git push upstream master

[vitorgalvao]

I’m fine with removing them. Now they have been in place for so long — and due to their usage and lack of usage — we have a better grasp for what needs to change about them.

I have for some time in my head a forming system for this, but it’ll take some time and work to flesh out.

In the meantime, I think having a single find_and_fix script that will only generate PRs and can be run by maintainers and users alike might be a good fit.

[vitorgalvao]

Done in #25936.