MNT Remove ColumnTransformer.remainder from get_metadata_routing if remainder is not an estimator (scikit-learn#31826)

Co-authored-by: Jérémie du Boisberranger <jeremie@probabl.ai>

Author: StefanieSenger

sklearn/compose/_column_transformer.py

@@ -1290,7 +1290,9 @@ def get_metadata_routing(self):
         # transformers, and whether or not a transformer is used at all, which
         # might happen if no columns are selected for that transformer. We
         # request all metadata requested by all transformers.
-        transformers = chain(self.transformers, [("remainder", self.remainder, None)])
+        transformers = self.transformers
+        if self.remainder not in ("drop", "passthrough"):
+            transformers = chain(transformers, [("remainder", self.remainder, None)])
         for name, step, _ in transformers:
             method_mapping = MethodMapping()
             if hasattr(step, "fit_transform"):