Remove unusued using statement (fixes #35840) (#35841)

* Remove unusued using statement (fixes #35840)
* Removing newline for EnableOpenAPI not needed

Author: timheuer

src/ProjectTemplates/Web.ProjectTemplates/content/WebApi-CSharp/Program.cs

@@ -8,10 +8,7 @@
 #if (OrganizationalAuth || IndividualB2CAuth)
 using Microsoft.Identity.Web;
 #endif
-#if (EnableOpenAPI)
-using Microsoft.OpenApi.Models;
-#endif
-#if (OrganizationalAuth || IndividualB2CAuth || GenerateGraph || EnableOpenAPI)
+#if (OrganizationalAuth || IndividualB2CAuth || GenerateGraph)
 
 #endif
 var builder = WebApplication.CreateBuilder(args);