data-plane-controller: dns_name should be optional for Azure privatelink

Author: mdibaiee

crates/data-plane-controller/src/stack.rs

@@ -163,6 +163,7 @@ pub struct AWSPrivateLink {
 pub struct AzurePrivateLink {
     pub service_name: String,
     pub location: String,
+    #[serde(default, skip_serializing_if = "String::is_empty")]
     pub dns_name: String,
     #[serde(default, skip_serializing_if = "String::is_empty")]
     pub resource_type: String,