cmd/k8s-operator: redact auth key from debug logs

[irbekrm]

Ensure that when auth key is provided to operator's proxy as part of tailscaled config, we don't print it, when the config is being printed for debugging purposes.

What the output looks like now:

{"level":"debug","ts":"2024-03-26T14:47:36Z","logger":"service-reconciler","msg":"creating a new Secret for the proxy with tailscaled config {\"Version\":\"alpha0\",\"Locked\":false,\"AuthKey\":\"**redacted**\",\"Hostname\":\"kuard1\",\"acceptDNS\":false,\"acceptRoutes\":false}","service-ns":"default","service-name":"kuard1"}

{"level":"debug","ts":"2024-03-26T14:46:04Z","logger":"service-reconciler","msg":"patching the existing proxy Secret with tailscaled config {\"Version\":\"alpha0\",\"Locked\":false,\"AuthKey\":\"**redacted**\",\"Hostname\":\"kuard1\",\"acceptDNS\":false,\"acceptRoutes\":false}","service-ns":"default","service-name":"kuard1"}

Updates#cleanup