Upgrade setup-miniconda to v3 due to deprecation

[btjanaka]

Description

Seems setup-miniconda@v2 uses Node 16 which raises a deprecation warning in GitHub Actions. Upgrading to v3 since that seems to be available.

Status

• [x] I have read the guidelines in CONTRIBUTING.md
• [x] I have formatted my code using yapf
• [x] I have tested my code by running pytest
• [x] I have linted my code with pylint
• [x] I have added a one-line description of my change to the changelog in HISTORY.md
• [x] This PR is ready to go