Move AKS tests to Standard_NC4as_T4_v3 (#678)

Author: 0x2b3bfa0

.github/workflows/smoke.yml

@@ -112,7 +112,7 @@ jobs:
         az aks create \
           --resource-group="tpiSmokeTestCluster$GITHUB_RUN_ID" \
           --name="tpiSmokeTestCluster$GITHUB_RUN_ID" \
-          --node-vm-size=Standard_NC6 \
+          --node-vm-size=Standard_NC4as_T4_v3 \
           --node-count=1 \
           --aks-custom-headers=UseGPUDedicatedVHD=true \
           --generate-ssh-keys