Update existing PRs for updates instead of opening new ones

[penguinpee]

Description

Currently, Packit opens a new PR for any new update it sees. For example, for fastavro Packit submitted PR #11 for updating to 1.9.0 and some time later PR #13 for updating to 1.9.1.

However, since both PRs are based on rawhide, automatic merging will fail for one or the other. The reason for fastavro not being updated yet, is a missing dependency introduced by upstream in 1.9.0. This will take some time and effort to solve.

Instead of submitting a new PR, Packit should amend the existing PR, if it is still open. That is update the title and add another commit with the changes for the latest release.

Benefit

The obvious benefit is a clear path forward for merging into rawhide, skipping intermediate versions. Updating an existing PR will also preserve the comments from that PR, possibly containing information why the update is still pending. Last but not least, additional changes may have been pushed to Packit's update branch by the package maintainers. Preserving these changes, the next update can take those into account.

Importance

I'd say this is medium importance. The benefits speak for themselves. With packages that see new releases frequently, this becomes more important.

Workaround

• There is an existing workaround that can be used until this feature is implemented.

Participation

• I am willing to submit a pull request for this issue. (Packit team is happy to help!)

[majamassarini]

We need this to be merged and deployed to be able to update PRs.