Tests are taking a long time to run

[espg]

Recently, our CI/CD test framework has increased to 25 to 30 minutes to run all tests (it was previously 3 to 6 minutes).

The hang is happening here:

Run conda env update --file environment.yml --name base
  conda env update --file environment.yml --name base
  shell: /usr/bin/bash -e {0}
  env:
    pythonLocation: /opt/hostedtoolcache/Python/3.10.17/x64
    LD_LIBRARY_PATH: /opt/hostedtoolcache/Python/3.10.17/x64/lib
/usr/share/miniconda/lib/python3.13/argparse.py:1[2](https://github.com/demiangomez/Parallel.GAMIT/actions/runs/15217355441/job/42805812758?pr=218#step:5:2)55: FutureWarning: `remote_definition` is deprecated and will be removed in 25.9. Use `conda env create --file=URL` instead.
  subnamespace, arg_strings = subparser.parse_known_args(arg_strings, None)
Channels:
 - defaults
 - conda-forge
Platform: linux-6[4](https://github.com/demiangomez/Parallel.GAMIT/actions/runs/15217355441/job/42805812758?pr=218#step:5:4)

This is not a result of any of our actual testing-- the image build is what is taking longer. This likely related to one of two issues:

1. We've added a new dependency recently which is causing conda to hang while it figures out how to resolve it.
2. The depreciation warning is a sign of something in the upstream build process which has changed, and using the depreciated version is now causing lag.

Here are possible fixes that we should look at to fix this:

1. Check if we've added any new dependencies recently. We could potentially remove them (if not needed for the library code), or change how they are being installed (i.e., have them install via pip rather than conda to avoid the conda solver).
2. Investigate and fix the depreciation warning within our github action configuration. This should probably be done at some point independently of if it is causing the slowdown, since we are being told it will convert from a warning to an error in the future.
3. Switch our build environment from conda to mamba. Conda is notoriously slow, which is why mamba exists. Alternatively, we could look at building purely by pip instead of conda or mamba... although I think we needed something beyond pip for non-python dependencies, so switching to mamba likely makes the most sense here.

[demiangomez]

Another thing I noticed is that while we setup python 3.10, the tests are actually running on Python 3.13.5. This is making the tests crash because we use some modules that depend on cgi, which has been deprecated. I will replaced these modules but still, we should probably run the tests on python 3.10

[espg]

Addressed in #221 . Note that because test run using the current workflow version, we won't see the impact from this until after it's merged, since the PR tests will still be using the prior version of the workflow and environment.yml file.