input: Write a function to remove all occurrences of a given element from a given array. Return the modified array.
  remove_element([2, 4, 5, 7, 4, 2], 4)
  assert remove_element([2, 4, 5, 7, 4, 2], 4)==[2, 5, 7, 2]
  assert remove_element([3, 5, 7, 2], 2)==[3, 5, 7]
  assert remove_element([], 1)==[]
  assert remove_element([1, 1, 1], 1)==[] 
  assert remove_element([4, 6, 8, 6, 4, 8], 6)==[4, 8, 4, 8]
output: def remove_element(arr, element):
      return [x for x in arr if x != element]