Update intersphinx links

[cvanelteren]

PR corrects the urls to enable cross referencing docs with sphinx.

[cvanelteren]

Now the intersphinx is loading again properly:

loading intersphinx inventory 'matplotlib' from https://matplotlib.org/stable/objects.inv ...
loading intersphinx inventory 'sphinx' from https://www.sphinx-doc.org/en/stable/objects.inv ...
loading intersphinx inventory 'python' from https://docs.python.org/3/objects.inv ...
loading intersphinx inventory 'numpy' from https://numpy.org/doc/stable/objects.inv ...
loading intersphinx inventory 'scipy' from https://docs.scipy.org/doc/scipy/objects.inv ...
loading intersphinx inventory 'xarray' from https://docs.xarray.dev/en/stable/objects.inv ...
loading intersphinx inventory 'cartopy' from https://scitools.org.uk/cartopy/docs/latest/objects.inv ...
loading intersphinx inventory 'basemap' from https://matplotlib.org/basemap/objects.inv ...
loading intersphinx inventory 'pandas' from https://pandas.pydata.org/pandas-docs/stable/objects.inv ...

[beckermr]

Thank you!

[cvanelteren]

There is still some funny business going on with the cartopy and basemap links not working but at least the objects.inv are now correctly pulled.