adding mamba install option

Is there a reason to use 'bash' as the processing shell? For one of my nbdev projects I need a package that is not available on pypi but is available on conda (mamba). I have an idea on how to add a mamba install option, but it needs 'bash -l' as the processing shell (login shell) in order to activate mamba environment.
At them moment I am using a hack (https://github.com/dmitryhits/HighResAnalysis/blob/master/.github/workflows/deploy.yaml) but I think it would be nicer if this option was available through a central nbdev repo.

P.S. I am referring to quarto-ghp action.