Convert assigning reviewer to GitHub Actions

[tetsuharuohzeki]

• I seem GitHub Actions would be reasonable way to change label & reviewers.
• GitHub Actions is still public beta and there are some limitations. We cannot remove it immediately after we convert assigning reviewer to GitHub Actions.

Related Issues

• Support command text inputted from GitHub's review comment #259

[tetsuharuohzeki]

I'm trying this in my private project, but the latency of GitHub Actions is still high. It does not react in a real time (It need ~30s to complete changing label including launch actions).

[tetsuharuohzeki]

I worked and open sourced these actions in my previous job:

• detect-unmergeable
  • I think popuko's unmergeable detection might be replaced with this action.
  • But there might be a problem about a latency which this action comments after the trunk is changed. popuko's one is tightly coupled with their merge queue. This kind of latency problem is rare case.
• auto-assign by comment
  • This command parser is fully scratched with JS but the base design is shared with popuko.
  • This parser has new syntax like r? userA || userB.