Remove Stale Branches

[MichaelCordingley]

Description:
Automatically remove branches that are not associated with an open issue and are more than X days stale.

Previously described in #620, which ironically closed due to staleness.

Justification:
Branches are another form of cruft that builds up and becomes stale.

Are you willing to submit a PR?
I'm probably not the best person to do so, else I would

[priyagupta108]

Hello @MichaelCordingley,
Thank you for the feature request. We will take a look and come back to you with the details!

[MichaelCordingley]

Thank you!

[nemchik]

Adding to this; I'd like to be able to delete stale branches that have already been merged. There is already an option to Automatically delete head branches but it would be nice to only perform this once a branch is considered stale (and has been merged).

Edit: To be clear, I would NOT want to automatically delete unmerged stale branches. I only want to delete stale branches that are associated with a pull request that has been merged.

[MichaelCordingley]

@priyagupta108 Checking in. Have you had a chance to take a look, yet?