Add missing project to Mvc.slnf (#33888)

Add missing project to file so the functional tests compile in Visual Studio.

src/Mvc/Mvc.slnf

@@ -110,6 +110,7 @@
       "src\\Mvc\\test\\WebSites\\RoutingWebSite\\Mvc.RoutingWebSite.csproj",
       "src\\Mvc\\test\\WebSites\\SecurityWebSite\\SecurityWebSite.csproj",
       "src\\Mvc\\test\\WebSites\\SimpleWebSiteWithWebApplicationBuilder\\SimpleWebSiteWithWebApplicationBuilder.csproj",
+      "src\\Mvc\\test\\WebSites\\SimpleWebSiteWithWebApplicationBuilderException\\SimpleWebSiteWithWebApplicationBuilderException.csproj",
       "src\\Mvc\\test\\WebSites\\SimpleWebSite\\SimpleWebSite.csproj",
       "src\\Mvc\\test\\WebSites\\TagHelpersWebSite\\TagHelpersWebSite.csproj",
       "src\\Mvc\\test\\WebSites\\VersioningWebSite\\VersioningWebSite.csproj",
@@ -137,4 +138,4 @@
       "src\\SignalR\\server\\SignalR\\src\\Microsoft.AspNetCore.SignalR.csproj"
     ]
   }
-}
+}