[FEAT] Add pytest.ini file and set asyncio_mode to auto

Created by: Hugo-Inmanta

Description

Add pytest.ini file and set asyncio_mode to auto

Part of inmanta/irt#1071

Merge procedure

Don't use the github built-in merge, but the process described here

git pull
git checkout master
git pull
git merge --squash issue/{issue-number}-{short description}
inmanta module commit -m "{Commit Message Here}" -r
git push
git push {tag} # push the tag as well

Then close the PR with a reference to the commit

Self Check:

Strike through any lines that are not applicable (~~line~~) then check the box

• Attached issue to pull request
• Changelog entry
• Version number is bumped to dev version
• Code is clear and sufficiently documented
• Sufficient test cases (reproduces the bug/tests the requested feature)
• Correct, in line with design
• End user documentation is included or an issue is created for end-user documentation (add ref to issue here: )

Reviewer Checklist:

• Sufficient test cases (reproduces the bug/tests the requested feature)
• Code is clear and sufficiently documented
• Correct, in line with design