fix ruff format error

Author: jelambrar96

maths/factorial.py

@@ -3,6 +3,7 @@
 """
 
 from functools import reduce
+from operator import mul
 
 
 def factorial(number: int) -> int:
@@ -31,7 +32,7 @@ def factorial(number: int) -> int:
         raise ValueError("factorial() only accepts integral values")
     if number < 0:
         raise ValueError("factorial() not defined for negative values")
-    value = 1 if number in {0, 1} else reduce(lambda x , y: x * y, range(1, number + 1))
+    value = 1 if number in {0, 1} else reduce(mul, range(1, number + 1))
     return value