Add `merge_group` trigger to required workflows for merge queue compatibility

[data-douser]

Problem

Repositories that use merge queues cannot merge PRs when these workflows are enforced as required via org-level rulesets. The merge queue times out because the workflows never start.

The merge queue fires a merge_group event on the temporary merge commit, but both workflows only trigger on pull_request and workflow_call — so they are never initiated, and the merge queue waits until its check response timeout is reached.

Per the GitHub docs on managing a merge queue:

If your repository uses GitHub Actions to perform required checks on pull requests in your repository, you need to update the workflows to include the merge_group event as an additional trigger. Otherwise, status checks will not be triggered when you add a pull request to a merge queue. The merge will fail as the required status check will not be reported.

Affected workflows:

• .github/workflows/dependency-review.yml
• .github/workflows/markdown-lint.yml

Fix

Add merge_group to the on: trigger in both workflow files:

on:
  merge_group:
  pull_request:
  workflow_call:

No other changes should be needed — the existing job steps are compatible with the merge_group event context.