[JENKINS-60663] - Capture pull request authors and add them to notable changes

[oleg-nenashev]

https://issues.jenkins-ci.org/browse/JENKINS-60661

This pull request adds capturing of authors from pull requests:

• All commit authors are included. "committers" are not included
• If GitHub REST API does not include GitHub ID, we query GitHub by email. At the moment it will unlikely help in any cases, but it will be useful for coauthors later.

Open Questions

• Should we always Add Pull request submitter to the list?
• Shout we reconsider changelog format in [WEBSITE-711] - Add changelog attribution with minor change support jenkins-infra/jenkins.io#2621 and [WEBSITE-711] - Add support of mentioning contributors in the Jenkins changelog jenkins-infra/jenkins.io#2620 to support non-GitHub users?

Sample YAMLs

Common PR

  - type: rfe
    pull: 4245
    authors:
    - daniel-beck
    message: |-
      TODO fixup changelog:
      PR title: Update script-security to 1.65
      Proposed changelog:
      * Update bundled version of Script Security Plugin to 1.65

PR without GitHub author in the commit metadata (jenkinsci/jenkins#4225):

  - type: rfe
    pull: 4225
    issue: 59152
    authors:
    - 'TODO: Stephan Reiter (stephan.reiter@msab.com)'
    message: |-
      TODO fixup changelog:
      PR title: [JENKINS-59152] - Reduce the default process soft-kill timeout from 2 minutes to 5 seconds
      Proposed changelog:
      * [JENKINS-59152] Default soft-kill timeout reduced to 5 seconds

PR with multiple authors - Need to find one, but not so helpful

[daniel-beck]

In 99% of cases co-authors from GitHub will have very minor contributions due to how GitHub does suggested changes; would just do it manually in notable cases.

[oleg-nenashev]

In 99% of cases co-authors from GitHub will have very minor contributions due to how GitHub does suggested changes; would just do it manually in notable cases.

Yes, I would also prefer to postpone that for now.

[MarkEWaite]

I think this is ready to merge. Thanks for doing it!