Set priority class to critical Flux components

Mark source-controller, kustomize-controller and helm-controller as system-cluster-critical.
This will reduce the chances of Flux controllers being evicted before other non-critical workloads.

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

manifests/bases/helm-controller/patch.yaml

@@ -4,3 +4,6 @@
 - op: add
   path: /spec/template/spec/serviceAccountName
   value: helm-controller
+- op: add
+  path: /spec/template/spec/priorityClassName
+  value: system-cluster-critical

manifests/bases/kustomize-controller/patch.yaml

@@ -4,3 +4,6 @@
 - op: add
   path: /spec/template/spec/serviceAccountName
   value: kustomize-controller
+- op: add
+  path: /spec/template/spec/priorityClassName
+  value: system-cluster-critical

manifests/bases/source-controller/patch.yaml

@@ -4,3 +4,6 @@
 - op: add
   path: /spec/template/spec/serviceAccountName
   value: source-controller
+- op: add
+  path: /spec/template/spec/priorityClassName
+  value: system-cluster-critical