Releasing files on the OCaml Forge has been disabled
As the OCaml Forge has basically been abandoned in favor of Github or other more modern methods of source control management, it has been decided a few years ago that it should be deprecated.
As part of that process, today, the possibility to upload new files has been disabled. If you have any projects that you mean to continue supporting and developing, know that there's no script or helper to assist you in migrating your project elsewhere. They will still be archived and served, though.