DEPR: core.index file (pandas-dev#49403)

Author: jbrockmendel

doc/source/whatsnew/v2.0.0.rst

@@ -157,6 +157,7 @@ Deprecations
 
 Removal of prior version deprecations/changes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+- Removed deprecated module ``pandas.core.index`` (:issue:`30193`)
 - Removed deprecated :meth:`Categorical.to_dense`, use ``np.asarray(cat)`` instead (:issue:`32639`)
 - Removed deprecated :meth:`Categorical.take_nd` (:issue:`27745`)
 - Removed deprecated :meth:`Categorical.mode`, use ``Series(cat).mode()`` instead (:issue:`45033`)