Deprecate ds.lazy() since Dataset is lazy already
diff --git a/python/ray/data/dataset.py b/python/ray/data/dataset.py
index 76d50afbe9244..199dca052df4f 100644
--- a/python/ray/data/dataset.py
+++ b/python/ray/data/dataset.py
@@ -4131,6 +4131,10 @@ def get_internal_block_refs(self) -> List[ObjectRef[Block]]:
         self._synchronize_progress_bar()
         return blocks
 
+    @Deprecated(
+        message="Dataset is lazy by default, so this conversion call is no longer "
+        "needed and this API will be removed in a future release"
+    )
     def lazy(self) -> "Dataset[T]":
         """Enable lazy evaluation.
 

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## Why are these changes needed?
https://github.com/ray-project/ray/issues/31639

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