fix: keep stream consumption loop until codegen port

Per @karpetrosyan's review feedback, keeping the stream consumption
loop that ensures all events are consumed before the iterator exits.
This will remain until the early exit improvement is ported to codegen.

Author: fede-kamel

src/anthropic/_streaming.py

@@ -107,6 +107,10 @@ def __stream__(self) -> Iterator[_T]:
 
             yield process_data(data=data, cast_to=cast_to, response=response)
 
+        # Ensure the entire stream is consumed
+        for _sse in iterator:
+            pass
+
     def __enter__(self) -> Self:
         return self
 
@@ -214,6 +218,10 @@ async def __stream__(self) -> AsyncIterator[_T]:
 
             yield process_data(data=data, cast_to=cast_to, response=response)
 
+        # Ensure the entire stream is consumed
+        async for _sse in iterator:
+            pass
+
     async def __aenter__(self) -> Self:
         return self