Readiness Endpoint support

[dvaldivia]

This PR introduces a readiness endpoint for the MinIO Tenant via the sidecar container. This endpoint is used to check
if the MinIO Tenant is ready to serve requests. The readiness endpoint is exposed at the /ready path.

The intention is to prevent kubernetes from routing traffic to a MinIO pod if it's not ready, while allowing MinIO pods
to talk to each other via the headless service with the publishNotReady flag set to true.

If MinIO returns 403 status, we deem that MinIO ready to receive traffic

This also removes MINIO_OPERATOR_VERSION to prevent rolling restarts on operator upgrades

With this change pods that are not "online" should not shown as ready

[cniackz]

gofumpt it please

[pjuarezd]

Linting is complaining

Running lint check
level=warning msg="[linters_context] running gomodguard failed: unable to parse module file go.mod: go.mod:3: invalid go version '1.22.0': must match format 1.23\ngo.mod:5: unknown directive: toolchain: if you are not using go modules it is suggested to disable this linter"
pkg/resources/statefulsets/minio-statefulset.go:19: File is not `gofumpt`-ed (gofumpt)
	"k8s.io/apimachinery/pkg/util/intstr"
pkg/resources/statefulsets/minio-statefulset.go:23: File is not `gofumpt`-ed (gofumpt)
	"strings"
pkg/resources/statefulsets/minio-statefulset.go:909: File is not `gofumpt`-ed (gofumpt)

pkg/resources/statefulsets/minio-statefulset.go:24: File is not `goimports`-ed (goimports)

make: *** [Makefile:50: lint] Error 1

[cesnietor]

evel=warning msg="[linters_context] running gomodguard failed: unable to parse module file go.mod: go.mod:3: invalid go version '1.22.0': must match format 1.23\ngo.mod:5: unknown directive: toolchain: if you are not using go modules it is suggested to disable this linter"

[dvaldivia]

@cesnietor I don't think that is an error, it's simply a warning

[pjuarezd]

Sidecar is still complaining on the import

level=warning msg="[linters_context] running gomodguard failed: unable to parse module file go.mod: go.mod:3: invalid go version '1.22.0': must match format 1.23\ngo.mod:5: unknown directive: toolchain: if you are not using go modules it is suggested to disable this linter"
Error: pkg/common/generate_config.go:29:1: exported: exported function AttachGeneratedConfig should have comment or be unexported (revive)
func AttachGeneratedConfig(tenant *miniov2.Tenant, fileContents string) string {
^
make: *** [Makefile:50: lint] Error 1
Error: Process completed with exit code 2.

[dvaldivia]

all lint problems taken care of @cesnietor @pjuarezd

[pjuarezd]

Could you add this feature to the V6.0 release notes in pr #2141 ?