Simplify time and space complexity comments

Removed redundant complexity explanations in docstring.

Author: Emilianouz

Sprint-1/Python/find_common_items/find_common_items.py

@@ -9,9 +9,9 @@ def find_common_items(
     """
     Find common items between two arrays.
 
-    Time Complexity: The time complexity is O(n + m) because we build a set from the second sequence in O(m) time and iterate through the first sequence in O(n) time.
-    Space Complexity: The space complexity is O(n + m) because we store up to all elements of the second sequence in a set and up to the common elements in additional storage. 
-    Optimal time complexity: The time complexity is O(n + m) and the space complexity is O(n + m).
+    Time Complexity: The time complexity is O(n + m) 
+    Space Complexity: The space complexity is O(n + m) 
+    Optimal time complexity: The time complexity is O(n + m) 
     """
     second_set = set(second_sequence)
     seen = set()