feat: add e2e test for compute-mig module

[andybubu]

---

Checklist

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass

[wiktorn]

Destroy fails on:

google_compute_disk.test-disk: Still destroying... [id=projects/wfe-e2e-***-prj/zones/europe-west4-b/disks/test-data-1, 10s elapsed]
module.nginx-mig.google_compute_instance_group_manager.default[0]: Still destroying... [id=projects/wfe-e2e-
...
module.nginx-mig.google_compute_instance_group_manager.default[0]: Destruction complete after 2m4s
module.nginx-template.google_compute_instance_template.default[0]: Destroying... [id=projects/wfe-e2e-***-prj/global/instanceTemplates/nginx-template-20240306111725727800000001]
module.nginx-template.google_compute_instance_template.default[0]: Still destroying... [id=projects/wfe-e2e-***-prj/global...nx-template-20240306111725727800000001, 10s elapsed]
module.nginx-template.google_compute_instance_template.default[0]: Destruction complete after 11s
╷
│ Error: Error waiting for Detaching disk from wfe-e2e-***-prj/europe-west4-b/instance-1: Operation was canceled by user ''.

For Stateful MIGs - Instance Config test case.

This is probably due to the fact that in instance that is created we have this:

     - disk {
          - auto_delete           = true -> null
          - boot                  = false -> null
          - device_name           = "data-1" -> null
          - disk_size_gb          = 0 -> null
          - interface             = "SCSI" -> null
          - labels                = {} -> null
          - mode                  = "READ_WRITE" -> null
          - provisioned_iops      = 0 -> null
          - resource_manager_tags = {} -> null
          - resource_policies     = [] -> null
          - source                = "test-data-1" -> null
          - type                  = "PERSISTENT" -> null
        }

If the instance is auto_deleting the disk, then we can't delete explicitly.