This is necessary with recent version of Traefik, because
it won't pick up Ingress resources that don't have an
IngressClass. So let's add an IngressClass and make it
the default.
Ingress v1beta1 is no longer served in Kubernetes 1.22, so we need
a version of Traefik that uses Ingress v1. Traefik supports Ingress
v1 in Traefik v2.5 and above. Right now (August 2021) the traefik
image is v2.4, so let's pin the image version to v2.5 (which is
currently in rc) so that the Ingress labs work correctly with
Kubernetes 1.22.
This bumps up all the deprecated RBAC YAML to v1.
It also updates a few vendored YAMLs.
Oh, and removes the unused Service resources from the Traefik YAMLs.
Closes#585
Jérôme Petazzoni