Update Optim requirement from 1.12.0 to 1.12.0, 2.0 in /test (#209)

Updates the requirements on [Optim](https://github.com/JuliaNLSolvers/Optim.jl) to permit the latest version.
- [Release notes](https://github.com/JuliaNLSolvers/Optim.jl/releases)
- [Changelog](https://github.com/JuliaNLSolvers/Optim.jl/blob/master/NEWS.md)
- [Commits](JuliaNLSolvers/Optim.jl@v1.12.0...v2.0.0)

---
updated-dependencies:
- dependency-name: Optim
  dependency-version: 2.0.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

test/Project.toml

@@ -42,7 +42,7 @@ JET = "0.9, 0.10, 0.11"
 KrylovKit = "0.10.2"
 LinearAlgebra = "1"
 NLsolve = "4.5.1"
-Optim = "1.12.0"
+Optim = "1.12.0, 2.0"
 Random = "1"
 SparseArrays = "1"
 StaticArrays = "1.9.13"