build(deps-dev): bump pytest from 6.2.5 to 7.1.2 in /backend

Bumps [pytest](https://github.com/pytest-dev/pytest) from 6.2.5 to 7.1.2.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@6.2.5...7.1.2)

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

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

Author: dependabot[bot]

backend/requirements-dev.txt

@@ -1,5 +1,5 @@
 fakeredis==1.8.2
 pre-commit==2.17.0
-pytest==6.2.5
+pytest==7.1.2
 pytest-responses==0.5.0
 responses==0.17.0