The script to copy information from duplicate bugs to the bugs they have been duplicated to should not revert signature changes

[amccreight]

Jens removed a signature, because it is invalid (I'll file a separate issue about that): https://bugzilla.mozilla.org/show_bug.cgi?id=1435343#c90

Then right after, bugbug added the same signature right back. It would be better if it didn't just flip the signatures right back after somebody changed them.

[marco-c]

Moved to the autonag repository as the problem is not in bugbug.

[marco-c]

I'm unsure whether we should actually do this, or if we should keep the same information across bugs in the same "duplicate group".

[suhaibmujahid]

@marco-c should we do this as part of #1760? If we merge copy_duplicate_info into duplicate_copy_metadata, this will be automatically solved.

[marco-c]

Sounds good!

[marco-c]

This is very rare though, so let's only do it if it's super quick.