Write a function that returns True if there exists at least one number that is larger than or equal to n.
exists_higher([5, 3, 15, 22, 4], 10) ➞ True
exists_higher([1, 2, 3, 4, 5], 8) ➞ False
exists_higher([4, 3, 3, 3, 2, 2, 2], 4) ➞ True
exists_higher([], 5) ➞ False
Return False for an empty array []