test: run watch cases concurrently

[LingyuCoder]

Summary

Run watch test cases concurrently.

Before:

After:

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This pull request introduces concurrent testing capabilities to the rspack-test-tools package. The changes span multiple files and primarily focus on adding support for concurrent test execution, modifying configurations, and handling concurrent tasks.

Concurrent Testing Support:

• packages/rspack-test-tools/src/test/creator.ts: Added methods and properties to handle concurrent test execution, including createConcurrentEnv, describeConcurrent, registerConcurrentTask, and tryRunTask. Introduced a concurrent option in the IBasicCaseCreatorOptions interface.

Checklist

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

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[codspeed-hq]

CodSpeed Performance Report

Merging #9541 will not alter performance

_{Comparing test/concurrent (089b819) with main (44f96be)}

Summary

✅ 7 untouched benchmarks