Bump pytest-cov from 6.1.0 to 6.1.1 in /back-end

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 6.1.0 to 6.1.1.
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v6.1.0...v6.1.1)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-version: 6.1.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

back-end/requirements.txt

@@ -16,7 +16,7 @@ starlette==0.46.1
 typing_extensions==4.12.2
 uvicorn==0.34.0
 pytest==8.3.5
-pytest-cov==6.1.0
+pytest-cov==6.1.1
 mysql-connector==2.2.9
 mysql-connector-python==9.2.0
 ddt==1.7.2