feat(blog): create post for 22.21.1

[github-actions]

Creates a new blog post for 22.21.1

Check this workflow's logs at https://github.com/nodejs/nodejs.org/actions/runs/18886416121.

[vercel]

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Project	Deployment	Preview	Updated (UTC)
nodejs-org	Ready	Preview	Oct 28, 2025 7:13pm

[Copilot]

Pull Request Overview

This PR adds a new blog post documenting the Node.js v22.21.1 (LTS) release. The file follows the standard Node.js release blog post format with metadata, commit history, download links, and SHASUMS for verification.

• Adds a release announcement for Node.js v22.21.1 (LTS) dated October 28, 2025
• Includes 36 commits covering various improvements and bug fixes across benchmarks, HTTP, libraries, tests, and tooling
• Provides download links and cryptographic checksums for all platform binaries

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[github-actions]

Lighthouse Results

URL	Performance	Accessibility	Best Practices	SEO	Report
/en	🟢 99	🟠 88	🟢 100	🟢 100	🔗
/en/about	🟢 100	🟢 93	🟢 100	🟠 88	🔗
/en/about/previous-releases	🟢 99	🟢 93	🟢 100	🟢 100	🔗
/en/download	🟢 98	🟢 96	🟢 100	🟢 100	🔗
/en/download/archive/current	🟢 100	🟢 100	🟢 96	🟢 100	🔗
/en/blog	🟢 100	🟢 100	🟢 96	🟢 100	🔗

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.57%. Comparing base (04bbc56) to head (2d8e1a8).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8284      +/-   ##
==========================================
+ Coverage   76.53%   76.57%   +0.04%     
==========================================
  Files         117      117              
  Lines        9733     9733              
  Branches      329      328       -1     
==========================================
+ Hits         7449     7453       +4     
+ Misses       2282     2278       -4     
  Partials        2        2              

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