build(deps-dev): Bump pytest-cov from 2.12.1 to 3.0.0

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 2.12.1 to 3.0.0.
- [Release notes](https://github.com/pytest-dev/pytest-cov/releases)
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v2.12.1...v3.0.0)

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

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

pyproject.toml

@@ -92,7 +92,7 @@ tomli = "^1.2.0"
 coverage = {extras = ["toml"], version = "^5.5"}
 mypy = "^0.910"
 pytest = "^6.2.5"
-pytest-cov = "^2.12.1"
+pytest-cov = "^3.0.0"
 time-machine = "^2.4.0"
 
 [tool.poetry.scripts]