chore(algorithms, sliding-window, max sum-subarray): account for all negative values

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: BrianLusina

algorithms/sliding_window/max_sum_of_subarray/__init__.py

@@ -10,7 +10,7 @@ def max_sum_subarray(nums: List[int], k: int) -> int:
 
     start = 0
     state = 0
-    max_sum = 0
+    max_sum = float('-inf')
 
     for end in range(n):
         state += nums[end]