feat: Adding cluster upgrade in blue-green with route53 example

[allamand]

What does this PR do?

This add a sample to allow Canary EKS cluster migration for ArgoCD stateless workloads using Route53 weighted records.

The changes in Route53 weighted are managed with Terraform variable from the 2 clusters.

Motivation

• Resolves #

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• Yes, I have added a new example under examples to support my PR
• Yes, I have created another PR for add-ons under add-ons repo (if applicable)
• Yes, I have updated the docs for this feature
• Yes, I ran pre-commit run -a with this PR

Note: Not all the PRs require a new example and/or doc page. In general:

• Use an existing example when possible to demonstrate a new addons usage
• A new docs page under docs/add-ons/* is required for new a new addon

For Moderators

• E2E Test successfully complete before merge?

Additional Notes

[askulkarni2]

Are these tags still required? Afaik only the "kubernetes.io/role/elb" = "1" is required.

Suggested change

	public_subnet_tags = {
	"kubernetes.io/cluster/${local.name}-blue" = "shared"
	"kubernetes.io/cluster/${local.name}-green" = "shared"
	"kubernetes.io/cluster/${local.name}-nodomain" = "shared"
	"kubernetes.io/role/elb" = "1"
	}
	private_subnet_tags = {
	"kubernetes.io/cluster/${local.name}-blue" = "shared"
	"kubernetes.io/cluster/${local.name}-green" = "shared"
	"kubernetes.io/cluster/${local.name}-nodomain" = "shared"
	"kubernetes.io/role/internal-elb" = "1"
	}
	public_subnet_tags = {
	"kubernetes.io/role/elb" = "1"
	}
	private_subnet_tags = {
	"kubernetes.io/role/internal-elb" = "1"
	}

[allamand]

i'll test this

[allamand]

So yes this is needed for Karpenter, we uses it in the subnet selector

  subnetSelector:
    kubernetes.io/cluster/{{ .Values.spec.clusterName }}: '*'
    kubernetes.io/role/internal-elb: '1' # to select only private subnets

Without this, your Karpenter nodes could be created in another VPC used maybe by another cluster