This updates `fmt` to the latest version and moves to just being a copy
of their repo to make updating easier (no editing their cmake / figuring
out which files to minimally include).
The motivation for this is now that we switched to C++ 20, there were a
ton of deprecated function usages that is going away in future compiler
versions. This gets rid of all those warnings.
* first pass
* first pass at shrinking fr3s
* only need to load vertices once
* avx2 detect and switch
* fix build
* another ifx'
* one more
* fix the sky and stupid math bug in size check
* temp
* working, but type pass got really slow
* clean up
* changelog and flip order
* clean up and add tests
* fix zero size array
* handle lambdas correctly
* another windows fix
* get gkernel and gkernel-h at least somewhat working in the offline tests
* strip comments from json
* switch hints to casts. online tests passing, offline passing up to gkernel
* variable retyping is added
* fix up casts in lets
* update
* move things to the common library and remove next_dir
* fix for windows
* one last windows fix
* last fix for real this time
* debug listener test
* fix listener threading bug
