ci: drop duplicate chromium install in storybook job

The job already runs 'playwright install --with-deps chromium' right
after pnpm install; the second install step before the visual step
re-downloaded the same browser for nothing. (S10)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -172,7 +172,5 @@ jobs:
       - name: Build Storybook
         run: pnpm --filter @repo/storybook build:storybook
       - run: pnpm test:stories
-      - name: Install Playwright browsers
-        run: pnpm exec playwright install chromium --with-deps
       - name: Visual regression
         run: pnpm test:visual