Bump pytest-cov from 3.0.0 to 4.0.0

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 3.0.0 to 4.0.0.
- [Release notes](https://github.com/pytest-dev/pytest-cov/releases)
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pytest-dev/pytest-cov/compare/v3.0.0...v4.0.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements/local.txt

@@ -18,7 +18,7 @@ pep8==1.7.1
 psycopg2-binary==2.9.5
 pylint==2.15.5
 pytest==6.2.5
-pytest-cov==3.0.0
+pytest-cov==4.0.0
 pytest-django==4.5.2
 pytest-xdist==3.0.2
 PyYAML==6.0