Bump redis from 5.0.0 to 5.0.8 in /back

Bumps [redis](https://github.com/redis/redis-py) from 5.0.0 to 5.0.8.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](redis/redis-py@v5.0.0...v5.0.8)

---
updated-dependencies:
- dependency-name: redis
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

back/requirements.txt

@@ -2,7 +2,7 @@ Flask==3.0.3
 gunicorn==21.2.0
 paho-mqtt==1.6.1
 requests==2.31.0
-redis==5.0.0
+redis==5.0.8
 flask_cors==4.0.0
 bcrypt==4.0.1
 google-auth==2.33.0