ci: add auto detected api change label on breaking change detecting in the CI

[rluvaton]

before merging this PR, the label auto detected api change should be created

Which issue does this PR close?

• Closes Breaking change detector: adding "auto detect api change" label on detection #21952

Rationale for this change

Without label the releaser and the people who write the change log in a new release won't find this using the regular
generate-changelog.py script and not using the existing api change label as described in the issue and in the workflow comment

What changes are included in this PR?

Are these changes tested?

No

Are there any user-facing changes?

No

[asolimando]

This is extremely cool, a big step forward to the automation of release notes for breaking changes, which are generally a nightmare to track in OSS with lots of side-effects on end-users, I wish any project had that detection + labeling machinery!

[rluvaton]

@kumarUjjawal can you please review?

[kumarUjjawal]

Per my understanding this adds the new auto detected api change label, but the changelog script does not use it yet. So a PR with only this new label may still be missing from the breaking changes section in release notes.

we should also update the changelog script to treat auto detected api change the same as api change?

[rluvaton]

yes, updated

[kumarUjjawal]

Looks good. Will have to create the label before merging this.

[rluvaton]

@Jefffrey @alamb @comphead can one of you create the label auto detected api change before merging?