BUG: fix extraction of conda version

[sfmig]

When creating a conda environment, the conda version is checked to determine the syntax of the command.

However, the version is currently extracted incorrectly. The command conda --version returns conda xx.xx.xx rather than the version string xx.xx.xx as the code assumes.

As a result, for conda version 23.3.1, we have conda_version = "conda 23.3.1" and conda_version >= "24.3.0" is evaluated as True, when it should be False.

This PR:

• adds a regexp to extract the conda version from the output of the conda --version command, and
• uses packaging.version.Version for a safer comparison of version strings.

It also pins setuptools following the recommendation given in PR #1426 to ensure CI passes.

Question:
Should we test that environments are created correctly for different conda versions?

[HaoZeke]

LGTM, thanks, could you add yourself to the author list as well? That'd be in docs/source/credits.rst

[HaoZeke]

Also, my apologies, I didn't see the question earlier, a test would be nice, but I think it can be added in later in a follow up (since I'm cutting a bugfix release now).