Avoid polluting service user account with micromamba files

[atteggiani]

Background

Currently, the micromamba create command within the testing job creates environment in a custom folder, but still uses/stores cache packages in the default location.
This ends up polluting the ~/.local folder of the service user, which should not happen.

Solution

Before running the micromamba create command, set the MAMBA_ROOT_PREFIX env variable to the temporary folder (deleted at the end of the workflow), so the cache would automatically be stored there instead.

Tasks carried out

• Added line to export MAMBA_ROOT_PREFIX env variable, to avoid polluting the service user with micromamba-related files
• Set tmp_dir equal to ${{ steps.create-tmp-dir.outputs.tmp_dir }} and replaced multiple occurrences of ${{ steps.create-tmp-dir.outputs.tmp_dir }} with it

[jo-basevi]

Line 163 has another instance of ${{ steps.create-tmp-dir.outputs.tmp_dir }} in cmd="${{ vars.MICROMAMBA_EXE }} run --prefix $env_prefix ... command. But otherwise, looks good to me!

[atteggiani]

Line 163 has another instance of ${{ steps.create-tmp-dir.outputs.tmp_dir }} in cmd="${{ vars.MICROMAMBA_EXE }} run --prefix $env_prefix ... command. But otherwise, looks good to me!

Oops thank you!

Addressed in 28c63a4cfb346513a046b5f5ba4cddfa35f9586b

[jo-basevi]

lgtm!