CompatHelper: bump compat for Optim to 2, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Optim package from 1.12 to 1.12, 2.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[github-actions]

Benchmark Results (Julia v1)

Time benchmarks

	main	0159308...	main / 0159308...
chemical_equilibrium/chemical_equilibrium (2222.51 K)	5.88 ± 0.027 ms	5.9 ± 0.049 ms	0.996 ± 0.0094
chemical_equilibrium/chemical_equilibrium (4549.37 K)	2.07 ± 0.0088 ms	2.1 ± 0.054 ms	0.989 ± 0.026
chemical_equilibrium/chemical_equilibrium (7875.9 K)	1.81 ± 0.046 ms	1.77 ± 0.04 ms	1.02 ± 0.035
fit/fit_spectrum	0.0302 h	0.03 h	1
synthesis/M dwarf/100 Å of APOGEE w/ water	7.45 s	7.43 s	1
synthesis/M dwarf/4000 Å - 8000 Å VALD solar	12.8 s	12.7 s	1.01
synthesis/M dwarf/APOGEE DR17 w/o water	9.88 s	9.79 s	1.01
synthesis/M dwarf/one wavelength	0.311 s	0.326 s	0.953
synthesis/sun/100 Å of APOGEE w/ water	0.819 s	0.816 s	1
synthesis/sun/4000 Å - 8000 Å VALD solar	6 s	5.84 s	1.03
synthesis/sun/APOGEE DR17 w/o water	4.78 s	4.68 s	1.02
synthesis/sun/one wavelength	0.132 s	0.131 s	1.01
time_to_load	2.85 ± 0.13 s	2.79 ± 0.048 s	1.02 ± 0.048

Memory benchmarks

	main	0159308...	main / 0159308...
chemical_equilibrium/chemical_equilibrium (2222.51 K)	12.6 k allocs: 5.69 MB	12.6 k allocs: 5.76 MB	0.988
chemical_equilibrium/chemical_equilibrium (4549.37 K)	11.5 k allocs: 1.92 MB	11.5 k allocs: 1.98 MB	0.966
chemical_equilibrium/chemical_equilibrium (7875.9 K)	11.4 k allocs: 1.63 MB	11.4 k allocs: 1.69 MB	0.961
fit/fit_spectrum	0.392 G allocs: 146 GB	0.403 G allocs: 147 GB	0.989
synthesis/M dwarf/100 Å of APOGEE w/ water	1.74 M allocs: 3.24 GB	1.74 M allocs: 3.24 GB	0.998
synthesis/M dwarf/4000 Å - 8000 Å VALD solar	8.49 M allocs: 7.11 GB	8.49 M allocs: 7.11 GB	0.999
synthesis/M dwarf/APOGEE DR17 w/o water	5.54 M allocs: 5.22 GB	5.54 M allocs: 5.23 GB	0.999
synthesis/M dwarf/one wavelength	1.15 M allocs: 0.286 GB	1.15 M allocs: 0.292 GB	0.982
synthesis/sun/100 Å of APOGEE w/ water	1.17 M allocs: 0.238 GB	1.17 M allocs: 0.242 GB	0.984
synthesis/sun/4000 Å - 8000 Å VALD solar	8.29 M allocs: 2.86 GB	8.29 M allocs: 2.86 GB	0.999
synthesis/sun/APOGEE DR17 w/o water	5.21 M allocs: 2.17 GB	5.21 M allocs: 2.17 GB	0.998
synthesis/sun/one wavelength	0.783 M allocs: 0.117 GB	0.784 M allocs: 0.121 GB	0.969
time_to_load	0.149 k allocs: 11.1 kB	0.149 k allocs: 11.1 kB	1

[ajwheeler]

Despite this being breaking, I don't think it would require any changes for us. This is probably worth doing, but we can't actually use 2.0 until/unless we replace NLsolve, because they share a common dependency.