Remove several obsolete mods

[anothersimulacrum]

Summary

SUMMARY: None

Purpose of change

Remove obsolete mods. I figure it's been long enough that old saves won't be a problem, but I could be wrong.
List: NW pack, Mundane Zombies, RL classes, sleep deprivation, zombie nightvision, fast healing, makeshift, necromancy

Describe the solution

git rm -r obsolete mods

Describe alternatives you've considered

Waiting longer.
Adding the mods removed to the mod test blacklist. I decided against this to prevent merge conflicts, it can be done later.

[ymber]

Make sure you catch any dead code these mods had in the engine.

[SirPendrak]

Sleep deprivation should be mainline, not removed.

[anothersimulacrum]

It has been mainlined, I'm removing the mod files that still existed for it.