fix: ignore missing reference on pr close

[wstrm]

What does this change

Ignore "Reference does not exist" error when closing a PR.

What issue does it fix

While closing a bunch of PRs I noticed that the program errored with:

INFO[0003] Closing 91 pull requests                     
INFO[0003] Closing                                       pr="<redacted> #163"
Error: DELETE https://<redacted>/git/refs/heads/<redacted>: 422 Reference does not exist []
Usage:
  multi-gitter close [flags]

Flags:
  -g, --base-url string     Base <...>

Notes for the reviewer

Maybe we should not try to close already closed PRs?

Checklist

• Made sure the PR follows the CONTRIBUTING.md guidelines
• Tests if something new is added

[lindell]

Which version did you run when this occurred?

It might have been fixed in:
v0.42.2 (bug appeared in v0.42.0)
#268

[wstrm]

I used latest master and tried it built from source. But I think my issue is different in that it's for already closed PRs. So it might make sense to retrieve closed status?

[lindell]

Ah, indeed, this fix was only for merged ones.

But the same mapping should be done for scm.PullRequestStatusClosed as was added for merged in #268.

[wstrm]

Okay, I can give adding that a try :)

[lindell]

Have you had any chance to look at this and are there any help needed in that case? :)

[lindell]

@wstrm Ping again.

Should I take a look at it instead?

[wstrm]

Hello! Sure :)

[lindell]

Should be fixed in: #290