Bump pytest-mock from 3.12.0 to 3.14.0 in /backend

Bumps [pytest-mock](https://github.com/pytest-dev/pytest-mock) from 3.12.0 to 3.14.0.
- [Release notes](https://github.com/pytest-dev/pytest-mock/releases)
- [Changelog](https://github.com/pytest-dev/pytest-mock/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-mock@v3.12.0...v3.14.0)

---
updated-dependencies:
- dependency-name: pytest-mock
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/requirements.txt

@@ -18,7 +18,7 @@ pdpyras==5.2.0
 psycopg2-binary==2.9.9
 pytest==8.1.1
 pytest-env==1.1.3
-pytest-mock==3.12.0
+pytest-mock==3.14.0
 pytest-sqlalchemy-mock==0.1.5
 python-dotenv==1.0.1
 python-json-logger==2.0.7