UseEnvironment does not work when using generic host based webhost #18499
Description
Seems like we override the configuration keys as the last entry in the host configuration when ConfigureWebHostDefaults is called. This might affect other host setting as well.
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.UseEnvironment("Staging")
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
// webBuilder.UseEnvironment("Staging"); // This works
});cc @Tratcher