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

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

Author: pre-commit-ci[bot]

machine_learning/losses/mean_squared_error.py

@@ -26,6 +26,7 @@ def mean_squared_error(y_true: np.ndarray, y_pred: np.ndarray) -> float:
 
     return mse
 
+
 if __name__ == "__main__":
     import doctest