docs: add v1.2 ecosystem updates

[chenjiahan]

Summary

This pull request includes updates to the blog documentation to announce improvements in the Rspack ecosystem. The most important changes include the addition of Angular support, the release of Rsbuild v1.2, and updates to the SWC plugin upgrade guide.

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[netlify]

✅ Deploy Preview for rspack canceled.

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[codspeed-hq]

CodSpeed Performance Report

Merging #9068 will not alter performance

_{Comparing ecosystem_doc_0121 (28ca773) with main (285e8e3)}

🎉 Hooray! codspeed-rust just leveled up to 2.7.2!

A heads-up, this is a breaking change and it might affect your current performance baseline a bit. But here's the exciting part - it's packed with new, cool features and promises improved result stability 🥳!
Curious about what's new? Visit our releases page to delve into all the awesome details about this new version.

Summary

✅ 3 untouched benchmarks