fix(eks_standard): break terraform locals cycle in cluster addons (#348)

needs_cloudwatch_iam_policy was derived from enabled_cluster_addons,
which depends on default_addons, which references
aws_iam_role.cloudwatch_agent_irsa[0].arn. That role's count then
referenced needs_cloudwatch_iam_policy, closing the cycle.

Source needs_cloudwatch_iam_policy directly from container_insights_enabled
(spec input), which already gates inclusion of the cloudwatch addon.

Author: unni-facets

modules/kubernetes_cluster/eks_standard/1.0/main.tf

@@ -119,7 +119,7 @@ locals {
 
   # Container Insights
   container_insights_enabled  = lookup(var.instance.spec, "container_insights_enabled", false)
-  needs_cloudwatch_iam_policy = contains(keys(local.enabled_cluster_addons), "amazon-cloudwatch-observability")
+  needs_cloudwatch_iam_policy = local.container_insights_enabled
 
   # KMS key for secrets encryption (only if enabled)
   enable_kms_key = lookup(var.instance.spec, "customer_managed_kms", true)