Old mappings aren't unloaded properly

[luttje]

More observations: It feels like every time the mappings are armed, the input becomes more sensitive

https://github.com/luttje/Key2Joy/assets/2738114/2f22bfe9-c75a-484f-bb5f-d5a4fd83517c

Originally posted by @luttje in https://github.com/luttje/Key2Joy/issues/60#issuecomment-1789238644

I've found that old mappings aren't unloaded when they're unarmed. Causing instability after toggling them on/off a few times.