CICD: Fix typos and add team label to release PR workflow

[algobarb]

Summary

After the previous release, noticed a few things to improve:

1. "Enhancement" sub-header should be "Enhancements" in the release notes
2. The ${RELEASE_TAG} is redundant when you add a title to the release. Removing release tag here aligns with our previous releases.
3. Authors in the Release notes should be prefaced with a @
4. Add Team Hyper Flow to the PRs so we can easily track and make sure PRs get merged and not forgotten
5. Swap out the changelog-builder with github api

Testing

Tested workflow in a separate repo.