Add `edited`, `ready_for_review`, `converted_to_draft` triggers for relevant checks

Effectively, @mikeharder found a very interesting edge-case where we do not properly retrigger `impact`/`summarize checks` when updating the _target_ branch of a PR, when the source branch doesn't change.

This is very small edge-case, but it _does_ exist.

This [PR in Mike's fork demonstrates the change of the target branch that isn't retriggering as we expect](https://github.com/mikeharder/azure-rest-api-specs/pull/39)

We need to investigate adding the following triggers to `pull_request` and `pull_request_target` across the repo:

```
- edited
- ready_for_review
- converted_to_draft
```

Inspect the repository's pull_request and pull_request_target workflow definitions and compare them with the linked pull request example. Identify every relevant workflow that runs impact or summarize checks, then add the three requested activity triggers consistently. Done means target-branch updates retrigger the checks without source-branch changes.

Written by the indexing model from the issue text.