x/build/cmd/gopherbot: generalize issue gardening tasks to work on all subrepos

[stamblerre]

Some of the subrepos maintain their own issue trackers, so it would be useful to have the general issue gardening tasks work on the subrepos. I've narrowed these tasks down to:

• Freezing old issues and closing issues in the WaitingForInfo state
• Automatically labeling proposals and documentation issues
• Applying labels from comments

[gopherbot]

Change https://golang.org/cl/233377 mentions this issue: cmd/gopherbot: extend gopherbot's general tasks to all subrepos

[dmitshur]

The general direction seems reasonable to me. We need to be mindful of all the issue trackers and issues that will be retroactively affected. I think it should be better to roll out any changes here gradually, to avoid the thundering herd problem and to make it easier to review what's being modified.

Are you okay with rolling this out for vscode-go issue tracker first, before we take on other repos? Since you and @hyangah are its owners, it should be easier to make progress on that repo (and for you to tell whether gopherbot is acting in a helpful way and not causing disruption).

/cc @golang/osp-team

[stamblerre]

Makes sense. I made that adjustment in the CL.

[gopherbot]

Change https://golang.org/cl/234023 mentions this issue: cmd/gopherbot: print referenced repo in closeCherryPickIssues

[gopherbot]

Change https://golang.org/cl/308790 mentions this issue: cmd/gopherbot: add more deleted issues to deletedIssues map