[script] Retrieve proper author and PR type when generating release notes

[mimowo]

What would you like to be added:

The release-notes script would retrieve the author of the fix from the parent PR.
Currently, the script retrieves the https://github.com/k8s-infra-cherrypick-robot as the author.

Similarly (less important, because it does not need to be repeated when re-generating notes) it would be great to retrieve the PR type (like kind or feature).

Why is this needed:

It takes time to manually adjust the release notes. Sometimes the notes are regenerated, and in total it can take something like 30min of manual chore. Similarly, we need to manually annotate type for the cherry-picks (/kind bug).

Example release in Kueue: kubernetes-sigs/kueue#2985
For this we have to manually adjust the notes. Example cherry-pick PR: kubernetes-sigs/kueue#2879.

[mimowo]

/cc @alculquicondor

[mbobrovskyi]

/assign

[mbobrovskyi]

Looks like we have initial logic to get original PR on #3468. It is not fully cover our problem but it would be great to merge it first.

[mimowo]

I see, thank you for letting us know. I'm wondering if we could tidy up the initial pr for the ease of reviewing