fix: tofu test failures by adding required outbound_type to network_profile mocks

OpenTofu v1.11.5 validates mock data against the azurerm provider schema, which requires outbound_type in network_profile. Without it, tests using workload_identity authentication fail with "Invalid mock/override field network_profile".

Author: damiankaminski

tests/authentication_client_secret.tftest.hcl

@@ -11,6 +11,7 @@ mock_provider "azurerm" {
         load_balancer_sku  = "standard"
         network_plugin     = "azure"
         network_policy     = "azure"
+        outbound_type      = "loadBalancer"
       }]
     }
   }

tests/authentication_workload_identity.tftest.hcl

@@ -12,6 +12,7 @@ mock_provider "azurerm" {
         load_balancer_sku  = "standard"
         network_plugin     = "azure"
         network_policy     = "azure"
+        outbound_type      = "loadBalancer"
       }]
     }
   }

tests/state_migration.tftest.hcl

@@ -12,6 +12,7 @@ mock_provider "azurerm" {
         load_balancer_sku  = "standard"
         network_plugin     = "azure"
         network_policy     = "azure"
+        outbound_type      = "loadBalancer"
       }]
     }
   }

tests/variable_validation.tftest.hcl

@@ -12,6 +12,7 @@ mock_provider "azurerm" {
         load_balancer_sku  = "standard"
         network_plugin     = "azure"
         network_policy     = "azure"
+        outbound_type      = "loadBalancer"
       }]
     }
   }