Update pytest-cov requirement from <5,>=3 to >=3,<6 (#1067)

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@v3.0.0...v5.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements/testing_without_asyncio.txt

@@ -1,4 +1,4 @@
 # pip install -r requirements/testing_without_asyncio.txt
 pytest>=6.2.5,<9
-pytest-cov>=3,<5
+pytest-cov>=3,<6
 black==22.8.0             # Until we drop Python 3.6 support, we have to stay with this version