Running `make dirhtml` in bindings/python/docs generates the following
error:
```
sphinx-build -b dirhtml -d build/doctrees source build/dirhtml
Running Sphinx v8.0.2
loading translations [en]... done
making output directory... done
Converting `source_suffix = '.rst'` to `source_suffix = {'.rst': 'restructuredtext'}`.
ERROR: Invalid value `None` in intersphinx_mapping['https://docs.python.org/']. Expected a two-element tuple or list.
```
This commit updates intersphinx_mapping to follow the latest docs [1]
[1] https://www.sphinx-doc.org/en/master/usage/extensions/intersphinx.html
Signed-off-by: Fredrik Lönnegren <fredrik@frelon.se>
# Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {'https://docs.python.org/': None}
+intersphinx_mapping = {'python': ('https://docs.python.org/3', None)}