fix: Switch GKE node pool creation to use cluster ID

What does this MR do?

When setting up CNH in Google Cloud using a zonal cluster, the node pools are failing to create: Variables:

{
  "geo_deployment": "ibaum-geo",
  "geo_site": "geo-primary-site",
  "machine_image": "ubuntu-2204-lts",
  "object_storage_buckets_force_destroy": true,
  "prefix": "ibaum-geo-primary",
  "project": "ibaum-d00cbcc6",
  "region": "us-central1",
  "sa_prefix": "ig-pri",
  "zone": "us-central1-a"
}

Error

Error: error creating NodePool: googleapi: Error 404: Not found: projects/ibaum-d00cbcc6/locations/us-central1/clusters/ibaum-geo-primary.
 Details:
 [
   {
     "@type": "type.googleapis.com/google.rpc.RequestInfo",
     "requestId": "0x1fa1bf496feba4a8"
   }
 ]
 , notFound

   with module.gitlab_ref_arch_gcp.google_container_node_pool.gitlab_supporting_pool[0],
   on ../../../../gitlab-environment-toolkit/terraform/modules/gitlab_ref_arch_gcp/gke.tf line 245, in resource "google_container_node_pool" "gitlab_supporting_pool":
  245: resource "google_container_node_pool" "gitlab_supporting_pool" {

If I hardcode in the path and use us-central1-a instead of us-central1, it works as well. I found using id to be the simpler path.

Related issues

Author's checklist

When ready for review, the Author applies the workflowready for review label and mention @gl-quality/get-maintainers:

• Merge request:
  • Corresponding Issue raised and reviewed by the GET maintainers team.
  • Merge Request Title and Description are up-to-date, accurate, and descriptive
  • MR targeting the appropriate branch
  • MR has a green pipeline
  • MR has no new security alerts in the widget from the Secret Detection and IaC Scan (SAST) jobs.
• Code:
  • Check the area changed works as expected. Consider testing it in different environment sizes (1k,3k,10k,etc.).
  • Documentation created/updated in the same MR.
  • If this MR adds an optional configuration - check that all permutations continue to work.
  • For Terraform changes: set up a previous version environment, then run a terraform plan with your new changes and ensure nothing will be destroyed. If anything will be destroyed and this can't be avoided please add a comment to the current MR.
• Create any follow-up issue(s) to support the new feature across other supported cloud providers or advanced configurations. Create 1 issue for each provider/configuration. Contact the Quality Enablement team if unsure.