[BUG] Handle repository/organization rename gracefully.

[akorchyn]

As the repository or organization changes name, we will have a duplicate in the repos list as we would track it as a new repo. We can also have duplicate PR entries for the same reason that we think it's a new repo.

We happened to have PR stuck in the merge loop because of that.
Probably, github has some identifier related to the repo/organization that we can link instead of the name/org. Need to research and come up with solution later on.

Copy of the telegram message with additional info

Related to the issue. I took a look. For now, I have manually staled the PR.

The issue happened as the repository was renamed from near_social_mobile to near_social_multiplatform.

The user created PR when it had the old name. But later, it was renamed, so the user had two entries in RoS (with old name and new name). The new name was successfully passed and executed. But the old one is stuck:

• Because our system tracks old name
• We see it's unmerged and check in Git Hub if it's merged. GitHub redirects us and returns a new name.
• We see PR is merged and try to execute an event. But first, we check if we didn't already mark it as merged. We check (using the new name from GitHub response) and see it's already merged. So it does nothing.

We need to think about it and create automatic migrations. But I think it's a pretty big task and not a priority.
I removed the old PR (as it's not needed and tracked by new name)

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