chore(codeowners): removing deprecated package

[zackarychapple]

The rspack-dev-middleware package was deprecated, this reference was missed.

Summary

Was helping someone debug an issue and was looking for this package. Was not able to find it in the codebase even though it looked like it was being published still. After verifying on NPM the package is deprecated.

Checklist

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

[netlify]

✅ Deploy Preview for rspack ready!

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[codspeed-hq]

CodSpeed Performance Report

Merging #9395 will not alter performance

_{Comparing zackarychapple:patch-1 (7bcf718) with main (39f13d9)}

🎉 Hooray! codspeed-node just leveled up to 4.0.0!

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

✅ 7 untouched benchmarks

[chenjiahan]

❤️