chore(deps): Update Terraform terraform-google-modules/project-factory/google to v18 (GoogleCloudPlatform#53)

Author: renovate-bot

test/setup/main.tf

@@ -16,7 +16,7 @@
 
 module "project" {
   source  = "terraform-google-modules/project-factory/google"
-  version = "~> 17.0"
+  version = "~> 18.0"
 
   name              = "ci-cloud-spanner"
   random_project_id = "true"