Update pytest-cov requirement from <6,>=4 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:production
...

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

pyproject.toml

@@ -39,7 +39,7 @@ dependencies = [
 
 [project.optional-dependencies]
 dev = ["pre-commit>=3.0.0"]
-tests = ["docker ~= 7.0", "pytest ~= 8.0", "pytest-cov >= 4,< 6", "pytest-durations ~= 1.3", "pytest-mock ~= 3.14"]
+tests = ["docker ~= 7.0", "pytest ~= 8.0", "pytest-cov >= 4,< 7", "pytest-durations ~= 1.3", "pytest-mock ~= 3.14"]
 docs = [
     "autodoc_pydantic>=2.0.0",
     "pydata-sphinx-theme",