chore(deps-dev): bump pytest-cov from 2.11.1 to 2.12.0

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 2.11.1 to 2.12.0.
- [Release notes](https://github.com/pytest-dev/pytest-cov/releases)
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v2.11.1...v2.12.0)

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

dev-requirements.txt

@@ -2,7 +2,7 @@ pydantic_openapi_helper==0.2.7
 coverage==5.5
 coveralls==2.2.0
 pytest==6.2.4
-pytest-cov==2.11.1
+pytest-cov==2.12.0
 attrs~=21.2.0
 Sphinx==3.5.4
 sphinx-bootstrap-theme==0.7.1