coverage calculation seems to be off for pull requests

[aepfli]

Somehow the coverage calculation for pull requests is off, see #112 - I did not change the code, but I improved the coverage by some percent.

We should investigate to have a better overview of what is changing between pull requests and how the coverage improved.

see https://app.codecov.io/gh/open-feature/python-sdk-contrib/commits for where our main history got stuck

[aepfli]

seems like there is no update on main coverage since #38 - this is the last info on codecov for the main branch, so I assume it might have happened afterwards.

#41 seems to have removed the build for main branch