[api] Bump pytest-cov from 6.1.1 to 6.2.1 in /backend

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 6.1.1 to 6.2.1.
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v6.1.1...v6.2.1)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-version: 6.2.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/poetry.lock

@@ -25,7 +25,7 @@ pylint = "^3.3.7"
 isort = "^6.0.1"
 pytest = "^8.4.1"
 pytest-mock = "^3.14.1"
-pytest-cov = "^6.1.1"
+pytest-cov = "^6.2.1"
 
 [build-system]
 requires = ["poetry-core"]