ci(ui): run the UI checks on a draft pull request

A draft skipped the whole validate job, so the branch that changes 200 UI
files was the one branch CI never looked at: lint, unit tests and build all
ran locally and nowhere else. A draft is where a check is worth the most —
it is the state a change sits in while it is still wrong.

The other workflows keep their gate. This one is dropped alone because the
comment-policy branches are drafts on purpose and their UI half is the part
with no other verification.

Author: otavio

.github/workflows/validate-ui.yml

@@ -11,7 +11,6 @@ on:
 jobs:
   validate:
     name: validate (${{ matrix.app }})
-    if: ${{ github.event.pull_request.draft == false }}
 
     strategy:
       fail-fast: false