Release tooling: Fix double run of publish workflow

[JReinhold]

What I did

#23393 introduced an "apply" step to the publishing workflow, that committed the version bump to next-release/latest-release. This had the unfortunate side-effect that this commit would trigger a secondary run of the publish workflow, running simultaneously with the already running publish workflow (albeit a little behind). The secondary run would be a no-op, but it would fail in the end. The existing workflow would complete without errors.

You can see how this played out in the release of 7.0.27, with this being the real run and this being the secondary run triggered.

This PR adds a guard against that, by cancelling the workflow if it's triggered by a commit with [skip ci], and then add that string to the version bump commit.

How to test

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[shilman]

LGTM