Add a couple more CLI tests; test create on Unixes

[mbargull]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

This adds a couple of additional CLI tests.

• mamba clean to test for No commands work after updating to mamba 1.5.3 mamba-org/mamba#3033 (comment) .
• mamba repoquery to test for repoquery not working anymore mamba-org/mamba#2994 .

Also test mamba create on osx- targets.
(Leaving out Windows as per the code comment; would probably work with invoking the .exe directly or prepending %PREFIX%\condabin to PATH manually beforehand, though).

Let's add these tests when a new version is released.
Adding it here as a "draft pull request" so we can just cherry-pick it.

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[mbargull]

This was included in gh-206.
Thanks @JohanMabille for merging this in!