Update gke.tf

update min GKE terraform api version to 1.22 to fix the following error:

Terraform has been successfully initialized!
Acquiring state lock. This may take a few moments...
google_container_cluster.primary: Creating...
╷
│ Error: googleapi: Error 400: No valid versions with the prefix "1.20" found., badRequest
│ 
│   with google_container_cluster.primary,
│   on gke.tf line 1, in resource "google_container_cluster" "primary":
│    1: resource "google_container_cluster" "primary" {
│ 
╵
Cleaning up project directory and file based variables
00:01
ERROR: Job failed: command terminated with exit code 1