Refine zero-copy streaming documentation by removing outdated information about eager conversion, emphasizing on-demand batch processing to prevent memory exhaustion.

Author: kosiew

docs/source/user-guide/dataframe/index.rst

@@ -153,11 +153,9 @@ Zero-copy streaming to Arrow-based Python libraries
 ---------------------------------------------------
 
 DataFusion DataFrames implement the ``__arrow_c_stream__`` protocol, enabling
-zero-copy, lazy streaming into Arrow-based Python libraries. Earlier versions
-eagerly converted the entire DataFrame when exporting to Python Arrow APIs,
-which could exhaust memory on large results. With the streaming protocol,
-batches are produced on demand so you can process arbitrarily large results
-without out-of-memory errors.
+zero-copy, lazy streaming into Arrow-based Python libraries. With the streaming 
+protocol, batches are produced on demand so you can process arbitrarily large 
+results without out-of-memory errors.
 
 .. note::