Codecov would add code comments (annotations) to PR diffs whenever a
line was not covered by tests. This isn't really useful to us right now
and just produces noise.
Most PRs change code where no tests have been written so far and where
adding tests is difficult. Codecov fails all those PRs.
These values should be adjusted once we have better integrated testing
into our workflow and have written better testing infrastructure for
modules and very tightly coupled components
patrick96