replace sea ice test with experiment

[juliasloan25]

We currently have a test for Eisenman sea ice (eisenman_seaice_tests.jl) which constructs and steps a simulation. This requires functionality from SciMLBase, so that package has to be added to the test/ environment. I suggest that we delete this test, and make sure that the experiment testing Eisenman sea ice makes sufficient checks. This way we can remove timestepping-related dependencies (SciMLBase.jl) from test, while maintaining that this sea ice model is tested.