Update pytest-cov requirement from ~=4.1 to ~=6.0

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@v4.1.0...v6.0.0)

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

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

test/requirements.txt

@@ -1,2 +1,2 @@
 pytest~=7.1
-pytest-cov~=4.1
+pytest-cov~=6.0