Fix docs custom retry logic example (#3276)

Co-authored-by: Douwe Maan <[email protected]>

Author: yf-yang

docs/retries.md

@@ -214,7 +214,7 @@ client = create_network_resilient_client()
 
 ```python {title="custom_retry_logic.py"}
 import httpx
-from tenacity import stop_after_attempt, wait_exponential
+from tenacity import retry_if_exception, stop_after_attempt, wait_exponential
 
 from pydantic_ai.retries import AsyncTenacityTransport, RetryConfig, wait_retry_after
 
@@ -230,7 +230,7 @@ def create_custom_retry_client():
 
     transport = AsyncTenacityTransport(
         config=RetryConfig(
-            retry=custom_retry_condition,
+            retry=retry_if_exception(custom_retry_condition),
             # Use wait_retry_after for smart waiting on rate limits,
             # with custom exponential backoff as fallback
             wait=wait_retry_after(