Omni: Operator can traverse image-factory API paths via unsanitized `talos_version` in CreateSchematic

Summary managementServer.CreateSchematic internal/backend/grpc/schematics.go passes the caller-controlled TalosVersion field directly to imageFactoryClient.OverlaysVersions, which embeds it verbatim into a fmt.Sprintf"/version/%s/overlays/official", talosVersion path template. url.URL.JoinPath...