Add versionadded to is_retryable docs

Author: robsdedude

src/neo4j/exceptions.py

@@ -227,6 +227,8 @@ def is_retryable(self) -> bool:
 
         :returns: :const:`True` if the error is retryable,
             :const:`False` otherwise.
+
+        .. versionadded:: 5.0
         """
         return False
 
@@ -406,6 +408,8 @@ def is_retryable(self) -> bool:
 
         :returns: :const:`True` if the error is retryable,
             :const:`False` otherwise.
+
+        .. versionadded:: 5.0
         """
         return False