Fix documentation builds (#6885)

* Fix documentation builds

* [skip-ci] Skip CI builds

Author: andersy005

doc/conf.py

@@ -328,7 +328,7 @@
     "iris": ("https://scitools-iris.readthedocs.io/en/latest", None),
     "numpy": ("https://numpy.org/doc/stable", None),
     "scipy": ("https://docs.scipy.org/doc/scipy", None),
-    "numba": ("https://numba.pydata.org/numba-doc/latest", None),
+    "numba": ("https://numba.readthedocs.io/en/stable/", None),
     "matplotlib": ("https://matplotlib.org/stable/", None),
     "dask": ("https://docs.dask.org/en/latest", None),
     "cftime": ("https://unidata.github.io/cftime", None),