Update pytest-cov requirement from >=4,<6 to >=4,<7

Updates the requirements on [pytest-cov](https://github.com/pytest-dev/pytest-cov) to permit the latest version.
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v4.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -47,7 +47,7 @@ tox = "4.16.0"
 
 [tool.poetry.group.test.dependencies]
 pytest = ">=7.1.2,<9.0.0"
-pytest-cov = ">=4,<6"
+pytest-cov = ">=4,<7"
 
 
 [tool.poetry.group.test-flake8.dependencies]