drop lockfile-lint

lockfile-lint doesn't support pnpm-lock.yaml. pnpm enforces tarball
integrity hashes on install, covering the core supply-chain concern.
The explicit allowlists (hosts, schemes, git URLs) are gone with it;
acceptable tradeoff for now.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/pull-request-comment.yml

@@ -131,9 +131,6 @@ jobs:
       - name: Lint check
         run: pnpm lint
 
-      - name: Lint lockfile
-        run: pnpm lockfile-lint
-
       - name: 🔤 Compile translations
         run: pnpm intl:build 2>&1 | tee i18n.log