Fix GitHub importer to import PR where source repo/fork was renamed/deleted
What does this MR do?
Fix "unknown repository" of a GitHub Pull Request after renamed or deleted the repo/fork. The GitHub Pull Requests API returns
repo attribute of the source branch for these PRs.
Why was this MR needed?
Without this fix, GitHub Pull Requests where the source repo/fork was renamed or deleted won't be imported.
Screenshots (if relevant)
Does this MR meet the acceptance criteria?
- Changelog entry added
API support added
- Added for this feature/bug
- All builds are passing
- Conform by the merge request performance guides
- Conform by the style guides
Branch has no merge conflicts with
master(if it does - rebase it please)
- Squashed related commits together
What are the relevant issue numbers?
Closes #24594 (closed)