Move to actually using JLLs

[staticfloat]

I believe we should be able to actually use the JLLs that ship with Julia as hinted at in this comment:

SparseArrays.jl/src/solvers/LibSuiteSparse.jl

Lines 3 to 6 in 38604c3

	# using SuiteSparse_jll (move to this when stdlibs have full support for jlls)
	const libumfpack = :libumfpack
	const libcholmod = :libcholmod
	const libspqr = :libspqr

This should standardize the library SONAME used by the main Julia distribution.

[ViralBShah]

What exactly do we need to do? Just pick up the names by importing SuiteSparse_jll instead of defining them by hand?

[vtjnash]

It looks like we still need to delete the vendored copies of the JLL files, if we want to claim to have actually be using the JLLs correctly now.
https://github.com/JuliaSparse/SparseArrays.jl/blob/main/src/solvers/LibSuiteSparse.jl and https://github.com/JuliaSparse/SparseArrays.jl/blob/main/src/solvers/lib

[vtjnash]

In particular, these values are wrong

SparseArrays.jl/src/solvers/lib/aarch64-apple-darwin20.jl

Lines 2400 to 2404 in 5fc5771

	const CHOLMOD_MAIN_VERSION = 4
	const CHOLMOD_SUB_VERSION = 0
	const CHOLMOD_SUBSUB_VERSION = 3

since there was no "compat" entry added in #378.

[ViralBShah]

If you are referring to the warnings about cholmod version mismatch, the issue there is that we are stuck in a bad place with a SuiteSparse upgrade. I think I need to revert part of the changes for SS7 for now until we can find a way to get #380 merged.

[vtjnash]

It is at least missing a compat entry for the JLL, since it is enforcing a CHOLMOD_*_VERSION value there, but not declaring that for the JLL dependency.

[ViralBShah]

That would need to be a version bound on SuiteSparse (inside SuiteSparse, each solver has its own version). So should there be a compat entry in https://github.com/JuliaLang/julia/blob/master/stdlib/SuiteSparse_jll/Project.toml?

[ViralBShah]

It looks like we still need to delete the vendored copies of the JLL files, if we want to claim to have actually be using the JLLs correctly now. https://github.com/JuliaSparse/SparseArrays.jl/blob/main/src/solvers/LibSuiteSparse.jl and https://github.com/JuliaSparse/SparseArrays.jl/blob/main/src/solvers/lib

I don't really understand what this means. These are autogenerated clang wrappers around suitesparse solvers that live in SparseArrays.jl. They used to live in SuiteSparse.jl, but I don't remember why we moved them to SparseArrays.jl.

cc @KristofferC

[vtjnash]

Ah, okay, I thought that was content from the JLL since it seemed to re-declare the version information from the JLL. There should be a compat entry in this package, which matches the CHOLMOD_*_VERSION value, based on the version of SuiteSparse_jll overall.

[ViralBShah]

It doesn't make sense for this package to have a compat entry that is the cholmod version. We just arbitrarily use the cholmod version (since that was the library that was changing the most at one point within suitesparse - but the individual components of suitesparse have completely different and independent version numbers). If anything, this package should have a compat entry that is the julia version.

[vtjnash]

It seems like currently (due to 691287e) this package is currently incompatible with all existing versions of SuiteSparse_jll, so that may also need to be reverted, then relanded with correct compat bounds