Update pytest-cov requirement from <7 to <8

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@v1.0...v7.0.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-version: 7.0.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

setup.py

@@ -78,7 +78,7 @@
           'test': [
               'httpx<0.29',
               'pytest<10',
-              'pytest-cov<7',
+              'pytest-cov<8',
           ],
       },
       entry_points={