Dependencies listed in xfstests_dev.py for xfstests-dev project are
outdated. This leads the xfstests_dev.py based integration tests to
fail. Update this dependency list using README of xfstests-dev project.
Also, remove code which is not relevant anymore (specifically, if-block
that checks and deals for 'python' and 'btrfs-progs-devel').
Fixes: https://tracker.ceph.com/issues/62556 Signed-off-by: Rishabh Dave <ridave@redhat.com>