Updating CI based on new error when setting up environment

[rt17603]

Description:

Updating environment.yml file to include new pinned packages.

Updating CI workflow to address new error: 'Error: The process '/usr/share/miniconda/condabin/conda' failed with exit code 1'

The CI still fails overall due to failing tests but conda / mamba is now able to build the environment successfully.

Type of Change:

[x] Bug fix

Other Comments:

• Applied change to workflow to use mambaforge as this should speed up CI / help fix the error message received based on : https://github.com/conda-incubator/setup-miniconda/issues/116.
• Updated environment.yml (and environment_variable.yml where needed) - See Issue #152 for details of errors
  • Added explicit cachetools dependency
  • Updated pinned packages (including pinning numpy based on pymc3 fails)

Tests still fail, but the conda environment can now be set up again.

Closes #152

[rt17603]

Looks good! Just needs the conflicts fixing.

Great thanks for taking a look - I resolved the conflict now in the environment.yml file.