Bots may be counted as external users

[andrew]

I noticed that some projects are listed as having an external contributor (pull request or issue where the author association is not OWNER or MEMBER) but the only external contributor is a bot.

Example: https://github.com/suptower/weather-cli which has one external contributor but it's dependabot[bot]

This should be fixable without needing any extra implementation in the issues service.

[andrew]

Also noting here that the current external_users? check probably doesn't work at all for non-github repositories as they don't have support for author_association (gitlab, gitea, forgejo etc)