Update pytest-cov requirement from <5.1.0,>=4.0.0 to >=4.0.0,<6.1.0

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@v4.0.0...v6.0.0)

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

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

Author: dependabot[bot]

src/test-requirements.txt

@@ -1,4 +1,4 @@
 httpx>=0.23.0,<0.30.0
 black>=22.10.0,<25.0.0
 pytest>=7.2.2,<9.0.0
-pytest-cov>=4.0.0,<5.1.0
+pytest-cov>=4.0.0,<6.1.0