Fixes this warning:

│ Warning: Argument is deprecated
│
│   with module.cluster.aws_iam_role.eks_cluster_role,
│   on .terraform/modules/cluster/cluster_iam.tf line 5, in resource "aws_iam_role" "eks_cluster_role":
│    5: resource "aws_iam_role" "eks_cluster_role" {
│
│ The inline_policy argument is deprecated. Use the aws_iam_role_policy resource instead. If Terraform should exclusively manage all inline policy associations (the current behavior of
│ this argument), use the aws_iam_role_policies_exclusive resource as well.