Bump terraform-aws-modules/eks/aws from 18.26.6 to 20.28.0

Bumps [terraform-aws-modules/eks/aws](https://github.com/terraform-aws-modules/terraform-aws-eks) from 18.26.6 to 20.28.0.
- [Release notes](https://github.com/terraform-aws-modules/terraform-aws-eks/releases)
- [Changelog](https://github.com/terraform-aws-modules/terraform-aws-eks/blob/master/CHANGELOG.md)
- [Commits](terraform-aws-modules/terraform-aws-eks@v18.26.6...v20.28.0)

---
updated-dependencies:
- dependency-name: terraform-aws-modules/eks/aws
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

eks.tf

@@ -14,7 +14,7 @@ provider "kubernetes" {
 
 module "eks" {
   source  = "terraform-aws-modules/eks/aws"
-  version = "18.26.6"
+  version = "20.28.0"
 
   manage_aws_auth_configmap = true
   cluster_name              = var.project_name