Charms for OpenStack Yoga supports both Ubuntu Focal and Jammy
which means Python 3.8 and Python 3.10. Managing dependencies
across those two versions is non-trivial and we need to build
the charm on the series the charm is supposed to support.
Switch to using a binary build which allows pip's dependency
resolution to work.
This patch also updates manila.py to align with
charm-interface-keystone commit
9ad5cade97e14b672ac859d34040353c3a40c7aa.
This patch also drops the impish bundle.
Change-Id: Ib3aea3fb26aa3e6282989b2758bdf4913ef58c28