Automation doesn't properly reset when new commits are pushed to PRs approved to merge

When a PR to private repo main branch has been `Ok-ApprovedToMerge`, and a new commit gets pushed to the PR, the automation should do "hard reset" - all approval labels should be removed. They currently are not, so if the new commit pushed after approval has breaking changes or needs ARM review, it won't happen - the automation will see the approval labels and consider all automated checks as passing.

Relevant PR:
https://github.com/Azure/azure-rest-api-specs-pr/pull/16435

This problem may be also present on PRs to other branches too, like public main. This way people could circumvent the process. Albeit so far we haven't seen anyone managing to successfully bypass our checks like that yet.

For details see [this Teams conversation](https://teams.microsoft.com/l/message/19:4f661242c446452e895359cc3ef45125@thread.tacv2/1707337955228?tenantId=72f988bf-86f1-41af-91ab-2d7cd011db47&groupId=0cab4ce9-7691-42ae-82e3-460d4346a710&parentMessageId=1707266772413&teamName=ARM%20API%20Reviewers&channelName=ARM%20linter%20rules&createdTime=1707337955228) for details.

Related (newer) issue:
- https://github.com/Azure/azure-sdk-tools/issues/7709