fix(ci): run Lighthouse on deployment_status instead of pull_request

[ryzrr]

Summary
Fixes - #207

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
webpack-doc-kit	Ready	Preview, Comment	Jul 22, 2026 4:51pm

[github-actions]

⚡ Lighthouse report

Audited the Vercel preview deployment: https://webpack-doc-m5wywxh3l-openjs.vercel.app

URL	Performance	Accessibility	Best Practices	SEO	Report
/	🟢 98	🟢 96	🟢 100	🟢 100	🔗
/about	🟢 99	🟢 97	🟢 100	🟢 100	🔗
/about/sponsors	🟢 99	🟢 95	🟢 100	🟢 100	🔗
/blog	🟢 99	🟢 96	🟢 100	🟢 100	🔗
/blog/posts/2026-02-04-roadmap-2026	🟢 98	🟢 93	🟢 100	🟢 100	🔗
/guides/getting-started	🟢 97	🟢 97	🟢 100	🟢 100	🔗
/docs/api/v5.x/options	🔴 68	🟢 96	🟢 100	🟢 100	🔗
/docs/loaders/css-loader	🟢 99	🟢 97	🟢 100	🟠 83	🔗

Scores are advisory (warn at 90); they do not fail the build. See .lighthouserc.json.