Update score() return type to support int | float

Mypy reported an incompatible return type because function_to_optimize may return float values. 
Updated score() return type from int to int | float for full compatibility.

Author: anandvenugopal-tech

searches/hill_climbing.py

@@ -29,7 +29,7 @@ def __init__(
         self.step_size = step_size
         self.function = function_to_optimize
 
-    def score(self) -> int:
+    def score(self) -> int | float:
         """
         Returns the output of the function called with current x and y coordinates.
         >>> def test_function(x, y):