Update pytest-cov requirement from ~=5.0 to ~=6.0 in /package

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@v5.0.0...v6.0.0)

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

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

package/test_requirements.txt

@@ -13,7 +13,7 @@ psutil==5.9.6  # same as Kedro for now
 pytest~=8.3
 pytest-asyncio~=0.21
 pytest-mock~=3.14
-pytest-cov~=5.0
+pytest-cov~=6.0
 ruff==0.7.0
 sqlalchemy-stubs~=0.4
 strawberry-graphql[cli]>=0.99.0, <1.0