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

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

Author: pre-commit-ci[bot]

data_structures/arrays/equilibrium_index_in_array.py

@@ -1,4 +1,3 @@
-
 """
 Find the Equilibrium Index of an Array.
 
@@ -90,4 +89,4 @@ def equilibrium_index(arr: list[int]) -> int:
 if __name__ == "__main__":
     import doctest
 
-    doctest.testmod()
+    doctest.testmod()