With the addition of the pixelization_abc in DM-32254 it is possible to add healpix pixelization support via healpy in python. A version of this has been done by Tatiana Goldina. This ticket is to use that framework and make it officially supported.

As a note, the default healpix ordering scheme in this implementation will be nest rather than ring because nest ordering has pixel locality making the RangeSet much more useful.