Update src/array_api_extra/_delegation.py

Co-authored-by: Guido Imperiale <crusaderky@gmail.com>

Author: NeilGirdhar

src/array_api_extra/_delegation.py

@@ -137,8 +137,8 @@ def one_hot(
     dtype : DType, optional
         The dtype of the return value.  Defaults to the default float dtype (usually
         float64).
-    axis : int or tuple of ints, optional
-        Position(s) in the expanded axes where the new axis is placed.
+    axis : int, optional
+        Position in the expanded axes where the new axis is placed. Default: -1.
     xp : array_namespace, optional
         The standard-compatible namespace for `x`. Default: infer.