chore(deps): bump pytest-cov from 4.1.0 to 5.0.0 in /backend

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 4.1.0 to 5.0.0.
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v4.1.0...v5.0.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

backend/requirements.txt

@@ -21,7 +21,7 @@ pre-commit==3.6.2
 pydantic-settings==2.2.1
 pytest==8.1.1
 pytest-asyncio==0.23.6
-pytest-cov==4.1.0
+pytest-cov==5.0.0
 pytest-xdist==3.5.0
 python-decouple==3.8
 python-dotenv==1.0.1