Change python tested

[danibene]

Description

The aim is to increase the minimum Python version tested from 3.7 to 3.8, since tests are currently failing on 3.7.

Proposed Changes

I changed the ci.yml function so that automated tests are only run with 3.8+. I also updated setup.cfg to require Python 3.8+.

Checklist

Here are some things to check before creating the pull request. If you encounter any issues, don't hesitate to ask for help :)

• I have read the contributor's guide.
• The base branch of my pull request is the dev branch, not the main branch.
• I ran the code checks on the files I added or modified and fixed the errors.
• I updated the changelog.