ci: drop the blank line yamlfmt rejects in pr-assessment.yaml

The rainix static job runs pre-commit over every file and the yamlfmt
hook rewrites this file to remove the blank line between the trigger
and the jobs block. This is the hook's own output committed, so the
job passes instead of failing on a diff.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Author: thedavidmeister

.github/workflows/pr-assessment.yaml

@@ -3,7 +3,6 @@ on:
   pull_request:
     types:
       - closed
-
 jobs:
   assess-pr-size-on-merge:
     uses: rainlanguage/github-chore/.github/workflows/pr-assessment.yml@main