Switch from mamba to conda to preserve environment.yaml env vars

[jsignell]

Closes #43

Adds a section to the notebook to capture the env vars as well.

[wildintellect]

This makes sense, hoping @batpad or @sunu can chime in if there's a reason not to do this. conda should be using mamba solver so build speed shouldn't change.

[batpad]

Looks like the build ran fine, so this seems fine to me. Will wait for @sunu to give a final 👍 - @wildintellect is this something we want to roll-out soon?

[sunu]

This looks great to me! The new environment variable checks in the notebook test are passing too.
Thanks so much, @jsignell!

[wildintellect]

@batpad we're going to also include #42 and then yes we'd like to deploy it next sprint (next week) after some light testing.