fix: skip the Genesis manifest prefetch in local scene development

Local scene development targets a local realm, so the prefetch would reach an
external host for a manifest that entrypoint never consumes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AwLgyC5zggzth1oggwnBd4

Author: eordano

Explorer/Assets/DCL/Infrastructure/Global/Dynamic/RealmController.cs

@@ -135,7 +135,11 @@ public async UniTask SetRealmAsync(URLDomain realm, CancellationToken ct)
             try
             {
                 serverAbout.Clear();
-                worldManifestProvider.PrefetchGenesisManifest(environment, ct);
+
+                // Local scene development runs against a local realm and must not reach out to
+                // the Genesis manifest host.
+                if (!isLocalSceneDevelopment)
+                    worldManifestProvider.PrefetchGenesisManifest(environment, ct);
 
                 GenericDownloadHandlerUtils.Adapter<GenericGetRequest, GenericGetArguments> genericGetRequest = webRequestController.GetAsync(new CommonArguments(url), ct, ReportCategory.REALM);
                 ServerAbout result = await genericGetRequest.OverwriteFromJsonAsync(serverAbout, WRJsonParser.Unity);