feat(flux/config): reduce concurrent workers

This was recommended as one of the suggestions in a bug report with the
similar issue fluxcd/helm-controller#149.

Author: qlonik

kubernetes/flux/config/flux.yaml

@@ -39,7 +39,7 @@ spec:
     - patch: |
         - op: add
           path: /spec/template/spec/containers/0/args/-
-          value: --concurrent=8
+          value: --concurrent=2
         - op: add
           path: /spec/template/spec/containers/0/args/-
           value: --kube-api-qps=500