Update Google Cloud machine types

[sombraSoft]

Description

This PR updates the rules/utils.go file to include missing Google Cloud machine types. The list of valid machine types was cross-referenced with the output of gcloud compute machine-types list to ensure completeness.

This update adds support for newer machine families including N4D, C4, X4, and various GPU/TPU configurations that were previously missing from the validation rules.

Changes

Added the following machine types to validMachineTypes:

A3 Series

• a3-edgegpu-8g-nolssd
• a3-ultragpu-8g-nolssd

C4 Series

• c4-highmem-288-lssd-metal
• c4-standard-288-lssd-metal

CT (TPU) Series

• ct3-hightpu-4t
• ct3p-hightpu-4t
• ct5p-hightpu-4t
• ct6e-standard-1t
• ct6e-standard-4t
• ct6e-standard-8t
• tpu7x-standard-4t

H4D Series

• h4d-highmem-192
• h4d-standard-192

N4D Series

High CPU:

• n4d-highcpu-2, n4d-highcpu-4, n4d-highcpu-8, n4d-highcpu-16, n4d-highcpu-32, n4d-highcpu-48, n4d-highcpu-64, n4d-highcpu-80, n4d-highcpu-96

High Mem:

• n4d-highmem-2, n4d-highmem-4, n4d-highmem-8, n4d-highmem-16, n4d-highmem-32, n4d-highmem-48, n4d-highmem-64, n4d-highmem-80, n4d-highmem-96

Standard:

• n4d-standard-2, n4d-standard-4, n4d-standard-8, n4d-standard-16, n4d-standard-32, n4d-standard-48, n4d-standard-64, n4d-standard-80, n4d-standard-96

X4 Series

• x4-1440-24t-metal
• x4-1920-32t-metal
• x4-960-12t-metal
• x4-960-16t-metal