fix: there's a missing 'v' in kubernetes_version

It's being parsed as an integer because there's a leading number in the text string; by adding the v, `terragrunt`, `tofu`, and `terraform` all will interpret the string correctly.

provider.tf

@@ -1,3 +1,4 @@
+# todo: report bug upstream to scott/terraform-provider-minikube
 provider "minikube" {
-  kubernetes_version = "1.30.0"
+  kubernetes_version = "v1.30.0"
 }