input: Write a python function to calculate mean and standard deviation of a list.
  assert compute_stats([1, 2, 3, 4, 5]) == (3.0, 2.0)
  assert compute_stats([10, 20, 30, 40, 50]) == (30.0, 14.142135623730951)
  assert compute_stats([5, 5, 5, 5]) == (5.0, 0.0)
output: def compute_stats(numbers):
      import math
  
      if not numbers:
          return (0.0, 0.0)
  
      mean = sum(numbers) / len(numbers)
      variance = sum((x - mean) ** 2 for x in numbers) / len(numbers)
      std_dev = math.sqrt(variance)
  
      return mean, std_dev