The Fabric Mods datapack pretends to be able to be disabled when it can't

[mrjasonn]

This does not match the behaviour of the fabric-convention-tags-v2 datapack which it literally cannot be disabled and won't pretend to be able to. This datapack should follow the same behaviour as the fabric-convention-tags-v2 datapack in regards to how this is handled. As mods are supposed to override vanilla, we shouldn't fix this by making it able to be disabled.