[api] Bump pytest from 8.3.5 to 8.4.1 in /backend

Bumps [pytest](https://github.com/pytest-dev/pytest) from 8.3.5 to 8.4.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@8.3.5...8.4.1)

---
updated-dependencies:
- dependency-name: pytest
  dependency-version: 8.4.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/poetry.lock

@@ -23,7 +23,7 @@ tomli = "^2.2.1"
 [tool.poetry.group.dev.dependencies]
 pylint = "^3.3.7"
 isort = "^6.0.1"
-pytest = "^8.3.4"
+pytest = "^8.4.1"
 pytest-mock = "^3.14.1"
 pytest-cov = "^6.1.1"