Add NumPy to intersphinx references. (#10809)

This PR adds `numpy` to the list of intersphinx references, which is needed to cross-reference numpy functions in cuDF's documentation. The Python intersphinx reference was updated to resolve a warning caused by a redirect. This also fixes a reference to `numpy.asarray`, which is a function (not a method).

Authors:
  - Bradley Dice (https://github.com/bdice)

Approvers:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

URL: #10809

docs/cudf/source/conf.py

@@ -197,8 +197,9 @@
 
 # Example configuration for intersphinx: refer to the Python standard library.
 intersphinx_mapping = {
-    "python": ("https://docs.python.org/", None),
+    "python": ("https://docs.python.org/3", None),
     "cupy": ("https://docs.cupy.dev/en/stable/", None),
+    "numpy": ("https://numpy.org/doc/stable", None),
 }
 
 # Config numpydoc

python/cudf/cudf/core/frame.py

@@ -538,7 +538,7 @@ def to_cupy(
         Parameters
         ----------
         dtype : str or numpy.dtype, optional
-            The dtype to pass to :meth:`numpy.asarray`.
+            The dtype to pass to :func:`numpy.asarray`.
         copy : bool, default False
             Whether to ensure that the returned value is not a view on
             another array. Note that ``copy=False`` does not *ensure* that
@@ -573,7 +573,7 @@ def to_numpy(
         Parameters
         ----------
         dtype : str or numpy.dtype, optional
-            The dtype to pass to :meth:`numpy.asarray`.
+            The dtype to pass to :func:`numpy.asarray`.
         copy : bool, default True
             Whether to ensure that the returned value is not a view on
             another array. This parameter must be ``True`` since cuDF must copy