Add newline at end of file for subarray_product_less_than_k.py

Author: ianlintner

src/interview_workbook/leetcode/sliding_window/subarray_product_less_than_k.py

@@ -43,4 +43,4 @@ def demo():
     tags=["array", "sliding window"],
     url="https://leetcode.com/problems/subarray-product-less-than-k/",
     notes="Two-pointer sliding window. Expand right, shrink left until product < k."
-)
+)