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:development
...

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

requirements-dev.txt

@@ -4,5 +4,5 @@
 black~=24.2
 pre-commit~=3.6
 pytest~=8.0
-pytest-cov~=4.1
+pytest-cov~=6.0
 wheel~=0.42