Update counting_sort.py (#1677)

Since the max function is called to find the maximum value, it doesn't seem necessary to traverse the list and call the max function several times to select the larger value.

codes/python/chapter_sorting/counting_sort.py

@@ -9,9 +9,7 @@ def counting_sort_naive(nums: list[int]):
     """计数排序"""
     # 简单实现，无法用于排序对象
     # 1. 统计数组最大元素 m
-    m = 0
-    for num in nums:
-        m = max(m, num)
+    m = max(nums)
     # 2. 统计各数字的出现次数
     # counter[num] 代表 num 的出现次数
     counter = [0] * (m + 1)