Simple End Disable

Disables the End. That's it. No config options, no commands.

Does so by just not teleporting entities that go through it, and instead showing the player a message.
Currently the message does not support translation, though if I have time to add it in, I will eventually do so.

This works server-side, though if you have it on your client, it will disable the end in Single Player (Why would one want that, I do not know).
To re-enable the End, just remove the mod.

Code adapted from github:ClemsonJames/progression, specifically this mixin