`setDefaultTimeout(undefined)` doesn't remove timeout

[mrleblanc101]

setDefaultTimeout(undefined) doesn't remove the default 5s timeout.
But setDefaultTimeout(null) does.
Except that it leads to a TypeScript error:

Argument of type 'null' is not assignable to parameter of type 'number | undefined'.

[mrleblanc101]

An argument of nothing or undefined will fallback to 5000 as it is the default value here:
https://github.com/open-rpc/client-js/blob/f443070b8a957b4416c66cfaf873f61892ce822d/src/transports/WebSocketTransport.ts#L29