Bump boot packages to filepath-1.4.100.0, unix-2.8.0.0 and Win32-2.13.3.0

Boot packages need an upgrade:

filepath-1.4.100.0, haskell/filepath@b7cad15d
unix-2.8.0.0, https://github.com/haskell/unix/commit/3be0223cee7395410915a127eba3acae5ff0b2f2
Win32-2.13.3.0, https://github.com/haskell/win32/commit/931497f7052f63cb5cfd4494a94e572c5c570642

Note that now unix and Win32 depend on filepath, which was not the case before. Given complicated relationship between filepath and template-haskell, @mpickering and @bgamari, could you possibly help with this bump?

CC @maerwald

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information