stream: remove unused _transformState

_transformState is no longer used since Transform was
simplified.

Refs: nodejs#32763

Author: ronag

lib/internal/streams/lazy_transform.js

@@ -59,11 +59,5 @@ ObjectDefineProperties(LazyTransform.prototype, {
     set: makeSetter('_writableState'),
     configurable: true,
     enumerable: true
-  },
-  _transformState: {
-    get: makeGetter('_transformState'),
-    set: makeSetter('_transformState'),
-    configurable: true,
-    enumerable: true
   }
 });