We recently discovered that the Codecov python package had been deprecated and was removed from PyPI today. Their guidance moving forward is to use their github action to integrated codecov.io coverage with your repo.
If you are maintaining a repo that has the codecov ptyhon package install and you’re seeing failures, remove the package from the relevant *.in file and run make upgrade to resolve the issue. If you want to continue to use codecov, you can ensure that the codecov action is being run after you run your test with coverage enabled.
Example PR where this was confirmed: build: Remove deprecated codecov package by timmc-edx · Pull Request #294 · openedx/edx-django-utils · GitHub
The relevant github actions workflow is here: edx-django-utils/ci.yml at master · openedx/edx-django-utils · GitHub