2572. Count the Number of Square-Free Subsets

You are given a positive integer 0-indexed array nums. A subset of the array nums is square-free if the product of its elements is a square-free integer. A square-free integer is an integer that is divisible by no square number other than 1. Return the number of square-free non-empty subsets of the array nums. Since the answer may be too large, return it modulo 109 + 7. A non-empty subset of n