Make the OpenAPI security scheme name for the Management API valid (#19762)

Author: kjac

src/Umbraco.Cms.Api.Management/DependencyInjection/ManagementApiConfiguration.cs

@@ -4,7 +4,7 @@ namespace Umbraco.Cms.Api.Management.DependencyInjection;
 
 internal static class ManagementApiConfiguration
 {
-    internal const string ApiSecurityName = "Backoffice User";
+    internal const string ApiSecurityName = "Backoffice-User";
     internal const string ApiTitle = "Umbraco Management API";
 
     internal const string ApiName = "management";