build(deps): update pytest-cov requirement in the test group

Updates the requirements on [pytest-cov](https://github.com/pytest-dev/pytest-cov) to permit the latest version.

Updates `pytest-cov` to 6.0.0
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v5.0.0...v6.0.0)

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

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

pyproject.toml

@@ -55,7 +55,7 @@ optional-dependencies.docs = [
 ]
 optional-dependencies.test = [
   "pytest~=8.2",
-  "pytest-cov~=5.0",
+  "pytest-cov~=6.0",
   "pytest-mock~=3.14",
   "pytest-randomly~=3.15",
   "pytest-recording~=0.13",