fix(browser): fix testNamePattern config

[hi-ogawa]

Description

• Closes Browser mode does not take --testNamePattern into account. #4226

I added a quick workaround similar to child/forks pool, such as:

vitest/packages/vitest/src/runtime/child.ts

Lines 97 to 108 in 8842faa

	function parsePossibleRegexp(str: string | RegExp) {
	const prefix = '$$vitest:'
	if (typeof str === 'string' && str.startsWith(prefix))
	return parseRegexp(str.slice(prefix.length))
	return str
	}
	function unwrapConfig(config: ResolvedConfig) {
	if (config.testNamePattern)
	config.testNamePattern = parsePossibleRegexp(config.testNamePattern) as RegExp
	return config
	}

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[hi-ogawa]

For now, I added this only for browser mode testing but not for vitest ui client since vitest ui doesn't seem to make use of testNamePattern.

Alternatively, we could fix this in serialization layer, but it didn't feel appropriate to put this custom logic in @vitest/ws-client unless maybe changing serialization library entirely to cover RegExp, Error, etc... so that there's no need for custom logic.

vitest/packages/ws-client/src/index.ts

Lines 79 to 80 in 76b6195

	serialize: stringify,
	deserialize: parse,