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

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

Author: pre-commit-ci[bot]

height_tree/tree.py

@@ -81,4 +81,4 @@ def tree_height_from_list(data: list[int]) -> int:
 if __name__ == "__main__":
     import doctest
 
-    doctest.testmod()
+    doctest.testmod()