Remove cockroach_version from the dedicated example (#167)

cockroach_version requires a feature flag to be set even if the version
is set to the latest version.  Customers who use this example nearly
always run into this issue. Removing this block since its not core to
the example.

examples/workflows/cockroach_dedicated_cluster/main.tf

@@ -19,12 +19,6 @@ variable "sql_user_password" {
   sensitive = true
 }
 
-variable "cockroach_version" {
-  type     = string
-  nullable = true
-  default  = "v22.2"
-}
-
 variable "cloud_provider" {
   type     = string
   nullable = false
@@ -99,7 +93,6 @@ provider "cockroach" {
 resource "cockroach_cluster" "example" {
   name              = var.cluster_name
   cloud_provider    = var.cloud_provider
-  cockroach_version = var.cockroach_version
   dedicated = {
     storage_gib      = var.storage_gib
     num_virtual_cpus = var.num_virtual_cpus