Doc fix: SliverChildBuilderDelegate is the lazy one (#26690)

packages/flutter/lib/src/widgets/sliver.dart

@@ -54,7 +54,7 @@ int _kDefaultSemanticIndexCallback(Widget _, int localIndex) => localIndex;
 /// While laying out the list, visible children's elements, states and render
 /// objects will be created lazily based on existing widgets (such as in the
 /// case of [SliverChildListDelegate]) or lazily provided ones (such as in the
-/// case of [SliverChildListDelegate]).
+/// case of [SliverChildBuilderDelegate]).
 ///
 /// ### Destruction
 ///