This patch drops K8up as operator/controller from all clusters. Since
it's not really used there is no point in keeping it around.

This patch removes some of the work that introduces sentinel as part of
the redis deployment. Sadly Mastodon isn't really sentinel compatible,
which makes it quite redundant. Instead we introduce a new service for
the redis-cluster, because the operator has this feature only in
unstable versions for now. This service will always point to the current
master node.

This patch replaces the call of common.names.fullname with the local
helper implementation, that is functionally identical but doesn't
require another dependency.

This patch adjust the base deployment of mastodon to use a
redis-operator based setup of redis, which should reduce potential
Single-Points-Of-Failure keeping all redis-based operations nice and HA.

This patch is needed to fully support disabling of redis authentication.
This allows to use the new defaults for the mastodon base deployment.
While it's probablky not recommended for a production deployment to
disable redis authentication, it doesn't hurt too much for a base
deployment.

Since no defaults change, it shouldn't matter anyway for users of this
chart.

This patch adjusts the central oauth2-proxy resource to use
`topologySpreadConstraints` instead of using `podAntiAffinity`. This
helps with reducing the risk of Pending Pods e.g. during updates when
also a pod config is adjusted.