[installers] use mamba instead of conda?

[maurov]

@newville this is relatively low priority for the moment, but I propose to move to mamba as package manager for installing Larch. If we keep using the Miniforge distribution, we could simply switch to mambaforge and then use mamba command instead.

What do you think?

I am proposing this because yesterday I did a Larch installation on Ubuntu 20.04 laptop and it was a pain. For a reason that I do not understand, both binary and installer failed. At the end the only way I managed to install Larch was manually with mamba.

If it is ok for you, I can take care updating the installer scripts and relative installation instructions in the documentation.

[newville]

@maurov yeah, that is definitely worth trying!