Ensure only whitelisted IPs can use Azure Search Service

Azure Search Service doesn't have a list of IPs that can access it, this may leave it open to malicious actors.

In Azure Console -

1. Open the Azure Portal and go to Cognitive Search.
2. Select the Cognitive Search service you wish to edit.
3. Under Settings, select Networking.
4. For Public Network Access, set to Selected Networks, then add a list of allowed IPs.
5. Configure Private network access as needed.

In Terraform -

1. In the azurerm_search_service resource, set allowed_ips to a list of allowed IPs.

References:
https://learn.microsoft.com/en-us/azure/search/search-what-is-azure-search
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/search_service#allowed_ips