fix: use of cached variable in internals

Author: bbatha

src/gradient/_client.py

@@ -329,7 +329,7 @@ def copy(
             access_token=access_token or api_key or self.access_token,
             model_access_key=model_access_key or inference_key or self.model_access_key,
             agent_access_key=agent_access_key or agent_key or self.agent_access_key,
-            agent_endpoint=agent_endpoint or self.agent_endpoint,
+            agent_endpoint=agent_endpoint or self._agent_endpoint,
             inference_endpoint=inference_endpoint or self.inference_endpoint,
             base_url=base_url or self.base_url,
             timeout=self.timeout if isinstance(timeout, NotGiven) else timeout,
@@ -641,7 +641,7 @@ def copy(
             access_token=access_token or api_key or self.access_token,
             model_access_key=model_access_key or inference_key or self.model_access_key,
             agent_access_key=agent_access_key or agent_key or self.agent_access_key,
-            agent_endpoint=agent_endpoint or self.agent_endpoint,
+            agent_endpoint=agent_endpoint or self._agent_endpoint,
             inference_endpoint=inference_endpoint or self.inference_endpoint,
             base_url=base_url or self.base_url,
             timeout=self.timeout if isinstance(timeout, NotGiven) else timeout,