update the link to scipy's intersphinx file (#5665)

Author: keewis

doc/conf.py

@@ -313,7 +313,7 @@
     "pandas": ("https://pandas.pydata.org/pandas-docs/stable", None),
     "iris": ("https://scitools-iris.readthedocs.io/en/latest", None),
     "numpy": ("https://numpy.org/doc/stable", None),
-    "scipy": ("https://docs.scipy.org/doc/scipy/reference", None),
+    "scipy": ("https://docs.scipy.org/doc/scipy", None),
     "numba": ("https://numba.pydata.org/numba-doc/latest", None),
     "matplotlib": ("https://matplotlib.org/stable/", None),
     "dask": ("https://docs.dask.org/en/latest", None),