input: Write a python function to generate a list of random hexadecimal numbers of length n.
  assert len(generate_hex_numbers(5))==5
  assert all(isinstance(num, str) for num in generate_hex_numbers(3))
  assert all(len(num) <= 8 for num in generate_hex_numbers(4))
output: import random
  
  def generate_hex_numbers(n):
      return [hex(random.randint(0, 0xFFFFFFFF))[2:] for _ in range(n)]