Update pytest-cov requirement from >=2.6.0 to >=7.1.0

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@v2.6.0...v7.1.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-version: 7.1.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -6,7 +6,7 @@ numba
 
 pytest>=3.6
 nbval>=0.9.0
-pytest-cov>=2.6.0
+pytest-cov>=7.1.0
 
 flake8>=3.5.0