Add runtimeClassName support to Tenant CRD

[dnskr]

Is your feature request related to a problem? Please describe.
The feature request related to the problem with files relabeling when MinIO pods run on nodes with enabled SELinux.
The solution described in the discussion and require runtimeClassName to be set on MinIO pods.

Describe the solution you'd like
Support for runtimeClassName needs to be added to Tenant CRD and tenant helm chart.

[steve-gray]

As per minio/minio#15217 and the associated discussions, without this work to enable skipping of most of the leg-work of an SELinux relabel, it's essentially impossible to use Minio in any modern managed Kubernetes environment. As most platforms default to an SELinux variant (EKS, OCI/EKS, AKS etc....), it essentially means a restart of Minio with a scaled number of files can take exponential amounts of time, and lead to low availability of the service.

[dnskr]

@Alevsk @dvaldivia Hi! Are you planning to work on this issue any time soon? If not, I can try to do it. Unfortunately I'm not familiar with go and operator code base. So I would appreciate your guidance or just one or two similar PRs as the examples.

[dvaldivia]

@dnskr it's a sort of an easy issue, I can work on this before the next release v4.5.0 which is going to be release early next week, or you can give it a try

[dnskr]

Great! In this case I would prefer to leave it to you, since I don't feel it's easy for me.

[dvaldivia]

@dnskr the PR is up, you can review it to get an idea on how to do this changes, it's sort of straight forward

[dvaldivia]

Most of the auto-generate code can be generated with our Makefile targets