Reevaluate code coverage measurements

[antonpirker]

Problem Statement

In our CI we did code coverage measurements: https://github.com/getsentry/sentry-python/blob/master/.github/workflows/ci.yml#L105-L109

          coverage erase
          ./scripts/runtox.sh '' --cov=tests --cov=sentry_sdk --cov-report= --cov-branch
          coverage combine .coverage*
          coverage xml -i
          codecov --file coverage.xml

But no one looked at them so we removed them.

Solution Brainstorm

Think about if we need code coverage and if the tools are the right ones.