fix: add controller service account and reference in deployment

Address review feedback: controller deployment was missing
serviceAccountName, running as default SA. Add dedicated
coder-k8s-controller ServiceAccount and reference it.

Author: ThomasK33

deploy/controller-deployment.yaml

@@ -13,6 +13,7 @@ spec:
       labels:
         app: coder-k8s-controller
     spec:
+      serviceAccountName: coder-k8s-controller
       containers:
         - name: controller
           image: ghcr.io/coder/coder-k8s:latest

deploy/rbac.yaml

@@ -1,5 +1,11 @@
 apiVersion: v1
 kind: ServiceAccount
+metadata:
+  name: coder-k8s-controller
+  namespace: coder-system
+---
+apiVersion: v1
+kind: ServiceAccount
 metadata:
   name: coder-k8s-apiserver
   namespace: coder-system