fix: store Math.random locally to prevent overriding it

[AriPerkkio]

Description

Store Math.random locally during module initialization. In Vitest if users mock Math.random and do not restore it correctly, Vitest will simply freeze and birpc timeouts.

Linked Issues

• Timeout Error when Calling "onAfterSuiteRun" in "birpc" Module during Test Run vitest-dev/vitest#3457 (reply in thread)

Additional context

I also checked all other public APIs and don't think there are any other APIs that need such handling.