fix: remove redundant OutputFileSystem.createReadStream

[colinaaa]

Summary

Fix an error occurred when upgrading to Rspack 1.6.0:

> tsc --build

packages/rspeedy/core/src/config/validate.ts(12,34): error TS(typia.createValidateEquals): unsupported type detected

- OutputFileSystem.createReadStream: unknown & unknown
  - nonsensible intersection

Related links

• The OutputFileSystem.createReadStream type has been added in fix(types): add createReadStream to OutputFileSystem interface #11963
• https://github.com/lynx-family/lynx-stack/actions/runs/18998640396/job/54262126029?pr=1909

Checklist

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

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[codspeed-hq]

CodSpeed Performance Report

Merging #12059 will not alter performance

_{Comparing colinaaa:colin/1101/createReadStream (66b43bb) with main (d808219)}

Summary

✅ 17 untouched

[chenjiahan]

Nice catch 👍