DOC: simplify dtype note in DataFrame.apply per review

Author: pranavkp71

pandas/core/frame.py

@@ -10629,7 +10629,7 @@ def apply(
               If you are just applying a NumPy reduction function this will
               achieve much better performance.
 
-         .. warning::
+         .. note::
 
             When ``raw=True``, the result dtype is inferred from the **first**
             returned value.