Fixes #1135 and #1136

[LaurentLesle]

Overview/Summary

Replace this with a brief description of what this Pull Request fixes, changes, etc.

This PR fixes/adds/changes/removes

1. Fixes Race condition results in InternalServerError when deploying in vhub a firewall, an express route gateway, vhub peering and routing intent #1135 - Race condition results in InternalServerError when deploying in vhub a firewall, an express route gateway, vhub peering and routing intent
2. Fixes Updating existing vnet dns_server with Azure firewall leads to azurerm_virtual_network error. #1136 - Updating existing vnet dns_server with Azure firewall leads to azurerm_virtual_network error.
3. Replace me

Breaking Changes

none

Testing Evidence

module.alz_connectivity.azurerm_virtual_hub_routing_intent.virtual_wan["/subscriptions/000000/resourceGroups/rg-prod-network-vwan/providers/Microsoft.Network/virtualHubs/lz-cl-hub-southeastasia/lz-cl-routingintent-southeastasia"]: Still creating... [6m40s elapsed]
module.alz_connectivity.azurerm_virtual_hub_routing_intent.virtual_wan["/subscriptions/000000/resourceGroups/rg-prod-network-vwan/providers/Microsoft.Network/virtualHubs/lz-cl-hub-southeastasia/lz-cl-routingintent-southeastasia"]: Creation complete after 6m41s [id=/subscriptions/000000/resourceGroups/rg-prod-network-vwan/providers/Microsoft.Network/virtualHubs/lz-cl-hub-southeastasia/routingIntent/lz-cl-routingintent-southeastasia]

Apply complete! Resources: 178 added, 0 changed, 0 destroyed.

Please provide any testing evidence to show that your Pull Request works/fixes as described and planned (include screenshots, if appropriate).

As part of this Pull Request I have

• Checked for duplicate Pull Requests
• Associated it with relevant issues, for tracking and closure.
• Ensured my code/branch is up-to-date with the latest changes in the main branch
• Performed testing and provided evidence.
• Updated relevant and associated documentation.

[LaurentLesle]

@matt-FFFFFF Any udpates?