Adding tls into required providers

infra/vultr-kubernetes/backend.tf

@@ -19,6 +19,11 @@ terraform {
       source  = "hashicorp/kubernetes"
       version = "2.37.1"
     }
+
+    tls = {
+      source  = "hashicorp/tls"
+      version = "4.1.0"
+    }
   }
 }