Libmamba solver Fixes e-mission/e-mission-docs#926

[nataliejschultz]

Setting libmamba as the solver in the setup_conda.sh makes both local runs and runs in GH actions almost twice as fast, while fixing the issue of Docker running out of space to run conda.sh.

While switching to mamba might be another option if different parts of conda start causing issues, this is a fix to the current issue that has the added benefit of making solving the environment much faster. See issue info here.

[nataliejschultz]

Testing info: I have tested libmamba both on GH actions and locally, by adding to the setup_conda.sh script:

hash -r
conda install -n base conda-libmamba-solver
conda config --set solver libmamba
conda config --set always_yes yes

Making libmamba the solver allowed the script to run successfully on GH actions, and was about twice as fast as previous runs. This increase in speed was also observed in my local tests. However, when running locally, I still had to increase docker resources up to 12GB.

@shankari I do not have a way to link this to the issue; see my messages on Teams for reference.