input: Write a python function to convert a list of strings to a list of integers.
  assert convert_strings_to_int(["1", "2", "3", "4"]) == [1, 2, 3, 4]
  assert convert_strings_to_int(["10", "20", "30"]) == [10, 20, 30]
  assert convert_strings_to_int(["0", "5", "15"]) == [0, 5, 15]
output: def convert_strings_to_int(strings):
      return [int(s) for s in strings]