Fix triage-pull-requests skipping PRs that open as draft

When a PR is opened as draft and later marked ready for review, the
check-requirements job's if filter excluded the ready_for_review action,
so the screening workflow never ran and unmet-requirements was never
applied. Add ready_for_review to the action filter so screening runs
when a draft PR transitions to requesting review.

Companion fix in desktop/gh-cli-and-desktop-shared-workflows updates the
called workflow's own filters to handle ready_for_review consistently.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: BagToad

.github/workflows/triage-pull-requests.yml

@@ -29,7 +29,7 @@ jobs:
   check-requirements:
     if: >-
       github.event_name == 'pull_request_target' &&
-      (github.event.action == 'opened' || github.event.action == 'reopened' || github.event.action == 'edited')
+      (github.event.action == 'opened' || github.event.action == 'reopened' || github.event.action == 'edited' || github.event.action == 'ready_for_review')
     uses: desktop/gh-cli-and-desktop-shared-workflows/.github/workflows/triage-pr-requirements.yml@main
     with:
       enable_pr_screening: true