chore: fix move labeler conflict PR

[ddevsr]

Description
Follow-up #7921

Move to workflows

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[ddevsr]

@kenjis Based on https://github.com/actions/labeler#permissions and https://github.com/prince-chrismc/label-merge-conflicts-action#faq---how-do-i-fix-resource-not-accessible-by-integration must using event pull_request_target

In order to add labels to pull requests, the GitHub labeler action requires write permissions on the pull-request. However, when the action runs on a pull request from a forked repository, GitHub only grants read access tokens for pull_request events, at most. If you encounter an Error: HttpError: Resource not accessible by integration, it's likely due to these permission constraints. To resolve this issue, you can modify the on: section of your workflow to use pull_request_target instead of pull_request (see example above). This change allows the action to have write access, because pull_request_target alters the context of the action and safely grants additional permissions.

[paulbalandan]

But using pull_request_target event is dangerous and not recommended.