[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

maths/harmonic_mean.py

@@ -30,4 +30,4 @@ def harmonic_mean(numbers: list[int | float]) -> float:
 if __name__ == "__main__":
     import doctest
 
-    doctest.testmod(verbose=True)
+    doctest.testmod(verbose=True)