Change Resource dunder hash to reduce collisions

Improves readability from the last commit

Author: dgetu

opentelemetry-sdk/src/opentelemetry/sdk/resources/__init__.py

@@ -234,8 +234,8 @@ def __eq__(self, other: object) -> bool:
         )
 
     def __hash__(self):
-        return hash(dumps(self._attributes, sort_keys=True)) + 31 * hash(
-            self._schema_url
+        return hash(
+            dumps(self._attributes, sort_keys=True) + "|" + self._schema_url
         )