Use the slim builder to avoid loading static assets (dotnet#2013)

- We're exposing a simple gRPC endpoint for the dashboard to talk to. We can avoid loading static assets completely (which causes all kinds of problems when things get out of sync).

Fixes dotnet#2012

src/Aspire.Hosting/Dashboard/DashboardServiceHost.cs

@@ -67,7 +67,10 @@ public DashboardServiceHost(
 
         try
         {
-            var builder = WebApplication.CreateBuilder();
+            var builder = WebApplication.CreateSlimBuilder();
+
+            // Turn on HTTPS
+            builder.WebHost.UseKestrelHttpsConfiguration();
 
             // Configuration
             builder.Services.AddSingleton(configuration);