Improve dotnet host runtime detection if pack has multiple different versions

Source/ThirdParty/nethost/nethost.Build.cs

@@ -35,6 +35,8 @@ public class nethost : ThirdPartyModule
             throw new Exception($"Missing NET SDK {DotNetSdk.MinimumVersion}.");
         if (!dotnetSdk.GetHostRuntime(options.Platform.Target, options.Architecture, out var hostRuntimePath))
         {
+            if (options.Target.IsPreBuilt)
+                return; // Ignore missing Host Runtime when engine is already prebuilt
             if (options.Flags.HasFlag(BuildFlags.GenerateProject))
                 return; // Ignore missing Host Runtime at projects evaluation stage (not important)
             throw new Exception($"Missing NET SDK runtime for {options.Platform.Target} {options.Architecture}.");