fix: remove misused type parameter from static pipe

[cartant]

Description:

The static pipe utility has a signature that accepts no argument yet has a type parameter - type parameters aren't really supposed to be used like this. This PR changes the return type for that signature to be typeof identity - which is what's returned. This means that the returned function can be used without losing the type of the argument passed to it:

const func = pipe();
const value = func(42); // type of value will be 42, not unknown

Calling pipe without passing arguments is something of an edge case, but I suppose it's more likely with spread tuples or something. Anyway, it's a misused type parameter, so we should remove it.

Related issue (if exists): #5557