Remove math.sqrt from the distance calculating function within DBSTRE…

…AM (resolve partially issue #1468).

river/cluster/dbstream.py

@@ -161,7 +161,7 @@ def __init__(
 
     @staticmethod
     def _distance(point_a, point_b):
-        return math.sqrt(utils.math.minkowski_distance(point_a, point_b, 2))
+        return utils.math.minkowski_distance(point_a, point_b, 2)
 
     def _find_fixed_radius_nn(self, x):
         fixed_radius_nn = {}