Get rid of `VFSUtils.lua`

Wait until games stop using it, then remove.

Here are some awaiting PRs.
https://github.com/techannihilation/TA/pull/1676

Games that still use it and need PRs:
https://github.com/GoogleFrog/spring1944
https://github.com/Arch-Shaman/ZK-Futurewars-Mod

AFAICT other games already don't use it, but double-check.

Start by checking references to VFSUtils.lua in RecoilEngine and reviewing PR 1676. Confirm whether spring1944 and ZK-Futurewars-Mod still use it, and check the listed repositories for migration work. Done means all known game dependencies are removed or addressed and VFSUtils.lua can be deleted safely.

Written by the indexing model from the issue text.