test(method-override): preserve query parameters during query override

[xu91102]

What this adds

Adds one test for query-based methodOverride().

The test verifies that the _method query parameter is removed before the request is re-dispatched, while unrelated query parameters are preserved for the overridden route.

This is a test-only change.

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

Verified locally with:

• npx vitest --run src/middleware/method-override/index.test.ts
• npx eslint src/middleware/method-override/index.test.ts
• npx prettier --check src/middleware/method-override/index.test.ts
• npx tsc --noEmit --pretty false
• git diff --check