Update project compatibilities for memory allocations

[MaxenceGollier]

@dpo
If we want no allocations in solvers, we need compatibility for versions of LinearOperators.jl and ShiftedProximalOperators.jl that come after JuliaSmoothOptimizers/LinearOperators.jl#337 and JuliaSmoothOptimizers/ShiftedProximalOperators.jl#125 respectively.
So version 0.2.1 for ShiftedProximalOperators.jl and release a new version for LinearOperators.jl. I can open a PR here once a new version of LinearOperators.jl has been released.

[MaxenceGollier]

This is done automatically in Julia; the version for LinearOperators that removes the allocations is 2.9.