build(deps-dev): bump pytest-responses from 0.4.0 to 0.5.0 in /backend

Bumps [pytest-responses](https://github.com/getsentry/pytest-responses) from 0.4.0 to 0.5.0.
- [Release notes](https://github.com/getsentry/pytest-responses/releases)
- [Changelog](https://github.com/getsentry/pytest-responses/blob/main/CHANGES)
- [Commits](getsentry/pytest-responses@0.4.0...0.5.0)

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

Author: dependabot[bot]

backend/requirements-dev.txt

@@ -1,5 +1,5 @@
 fakeredis==1.4.5
 pre-commit==2.11.1
 pytest==6.2.2
-pytest-responses==0.4.0
+pytest-responses==0.5.0
 responses==0.12.1