fix: remove VnetName check from common cloudConfig package (Azure#956)

VnetName check only on fleet-member-agent

Author: britaniar

pkg/utils/cloudconfig/azure/config_test.go

@@ -543,8 +543,9 @@ func TestNewCloudConfigFromFile(t *testing.T) {
 			filePath: "./test/azure_valid_config.json",
 			wantConfig: &CloudConfig{
 				ARMClientConfig: azclient.ARMClientConfig{
-					Cloud:    "AzurePublicCloud",
-					TenantID: "00000000-0000-0000-0000-000000000000",
+					Cloud:     "AzurePublicCloud",
+					TenantID:  "00000000-0000-0000-0000-000000000000",
+					UserAgent: "fleet-member-agent",
 				},
 				AzureAuthConfig: azclient.AzureAuthConfig{
 					UseManagedIdentityExtension: true,