Defaults channel in requirements-test.yml is deprecated

[lauramurgatroyd]

Description

When running the conda github actions we get the following error:

/usr/share/miniconda/lib/python3.12/site-packages/conda/base/context.py:198: FutureWarning: Adding 'defaults' to channel list implicitly is deprecated and will be removed in 25.3.

To remove this warning, please choose a default channel explicitly with conda's regular configuration system, e.g. by adding 'defaults' to the list of channels:

conda config --add channels defaults

For more information see https://docs.conda.io/projects/conda/en/stable/user-guide/configuration/use-condarc.html

This is because in our requirements file we list 'defaults' as a channel:

CIL/scripts/requirements-test.yml

Line 19 in c79eda4

- defaults

Environment

import cil, sys
print(cil.version.version, cil.version.commit_hash, sys.version, sys.platform)