Implement a generic Pop<T> that takes an Array T and returns an Array without it's last element.

For example

type arr1 = ['a', 'b', 'c', 'd'];
type pop1 = Pop<arr1> // expected to be ['a', 'b', 'c']

type arr2 = [3, 2, 1]
type pop2 = Pop<arr2> // expected to be [3, 2]