build(deps-dev): bump pre-commit from 2.8.2 to 2.9.2 in /backend

Bumps [pre-commit](https://github.com/pre-commit/pre-commit) from 2.8.2 to 2.9.2.
- [Release notes](https://github.com/pre-commit/pre-commit/releases)
- [Changelog](https://github.com/pre-commit/pre-commit/blob/master/CHANGELOG.md)
- [Commits](pre-commit/pre-commit@v2.8.2...v2.9.2)

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

Author: dependabot[bot]

backend/requirements-dev.txt

@@ -1,5 +1,5 @@
 fakeredis==1.4.4
-pre-commit==2.9.0
+pre-commit==2.9.2
 pytest==6.1.2
 pytest-responses==0.4.0
 responses==0.12.1