chore(deps): update pytest requirement in /backend

Updates the requirements on [pytest](https://github.com/pytest-dev/pytest) to permit the latest version.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](https://github.com/pytest-dev/pytest/compare/8.2.2...8.3.2)

---
updated-dependencies:
- dependency-name: pytest
  dependency-type: direct:production
...

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

backend/requirements.txt

@@ -76,5 +76,5 @@ duckduckgo-search~=6.2.1
 
 ## Tests
 docker~=7.1.0
-pytest~=8.2.2
+pytest~=8.3.2
 pytest-docker~=3.1.1