Remove launch stage from Cloud Run GPU job test/example (#15527)

Author: yanweiguo

mmv1/templates/terraform/examples/cloudrunv2_job_gpu.tf.tmpl

@@ -2,7 +2,6 @@ resource "google_cloud_run_v2_job" "{{$.PrimaryResourceId}}" {
   name     = "{{index $.Vars "cloud_run_job_name"}}"
   location = "us-central1"
   deletion_protection = false
-  launch_stage = "BETA"
   template {
     template {
       containers {

mmv1/third_party/terraform/services/cloudrunv2/resource_cloud_run_v2_job_test.go.tmpl

@@ -1041,7 +1041,6 @@ func testAccCloudRunV2Job_cloudrunv2JobWithGpu(context map[string]interface{}) s
   resource "google_cloud_run_v2_job" "default" {
     name     = "%{job_name}"
     location = "us-central1"
-    launch_stage = "BETA"
     deletion_protection = false
     template {
       template {