Allow upgrading AWS Terraform provider to v4.x

* https://github.com/hashicorp/terraform-provider-aws/releases/tag/v4.0.0

aws/flatcar-linux/kubernetes/workers/versions.tf

@@ -3,7 +3,7 @@
 terraform {
   required_version = ">= 0.13.0, < 2.0.0"
   required_providers {
-    aws      = ">= 2.23, <= 4.0"
+    aws      = ">= 2.23, <= 5.0"
     template = "~> 2.2"
 
     ct = {

aws/flatcar-linux/kubernetes/workers/workers.tf

@@ -33,13 +33,11 @@ resource "aws_autoscaling_group" "workers" {
   # used. Disable wait to avoid issues and align with other clouds.
   wait_for_capacity_timeout = "0"
 
-  tags = [
-    {
-      key                 = "Name"
-      value               = "${var.name}-worker"
-      propagate_at_launch = true
-    },
-  ]
+  tag {
+    key                 = "Name"
+    value               = "${var.name}-worker"
+    propagate_at_launch = true
+  }
 }
 
 # Worker template