update release note generation

[radTuti]

Description

• ensure milestone is closed before generating release notes
• ensure there are no open PRs in the milestone

For PR author

• [ ] Tests for change.
• [ ] If changing pkg/apis/, run make gen-files
• [ ] If changing versions, run make gen-versions

For PR reviewers

A note for code reviewers - all pull requests must have the following:

• [ ] Milestone set according to targeted release.
• [ ] Appropriate labels:
  • kind/bug if this is a bugfix.
  • kind/enhancement if this is a a new feature.
  • enterprise if this PR applies to Calico Enterprise only.

[tmjd]

Seems like these checks on the milestone and PRs in the milestone should perhaps be done as part of the release-prep also or there should be a check before doing the "Rerun" in semaphore.

[radTuti]

Seems like these checks on the milestone and PRs in the milestone should perhaps be done as part of the release-prep also or there should be a check before doing the "Rerun" in semaphore.

I have moved the checking milestones and PRs in milestones to "Preparing for the release" section in the releasing docs. The check in the release notes are additional sanity check. I have also added to the release-prep task to handle checking and closing the milestone