keyrings/cassandra: Update
This should unstuck the storage build.
$ wget https://downloads.apache.org/cassandra/KEYS -0 ./keyrings/cassandra.asc
$ then edit it to drop the non pgp block which prevents the thing from working
Related to swh/infra/sysadm-environment#3578 (closed)
Test Plan
tox is happy.
Real test would be to push and check if it unstucks the build?
Migrated from D6276 (view on Phabricator)