[BUG] Changelog Verifier GitHub Action generates seven notification emails

[dbwiddis]

What is the bug?

When submitting a pull request without a change log entry, seven notification emails are sent. (Eight if the submitter is not a codeowner.)

How can one reproduce the bug?

Submit a pull request without a change log entry or skip-changelog tag.

What is the expected behavior?

Zero or one notification emails to project maintainers.

Do you have any screenshots?

Do you have any additional context?

The action is set to run on types: [opened, edited, review_requested, synchronize, reopened, ready_for_review, labeled, unlabeled] so it runs:

• when the PR is opened
• when the backport label is applied
• when reviews are requested (5 notifications, one for each of the 5 codeowners other than the submitter)

Suggested fix:

• remove review_requested type
• filter labeled type to only care about adding or removing the two labels associated with this workflow

[dbwiddis]

FYI, the problem is worse on OpenSearch core:

[dbwiddis]

Fixed in #646