perf: flag dependency exports plugin

[SyMind]

Summary

Checklist

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

[netlify]

✅ Deploy Preview for rspack canceled.

Name	Link
🔨 Latest commit	48808da
🔍 Latest deploy log	https://app.netlify.com/sites/rspack/deploys/67ac4c3c8985d100087a73b9

[codspeed-hq]

CodSpeed Performance Report

Merging #9245 will not alter performance

_{Comparing perf-flag-exports-plugin (48808da) with main (b104095)}

Summary

✅ 6 untouched benchmarks
🆕 1 new benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
🆕	flag_dependency_exports	N/A	22.4 ms	N/A

[SyMind]