Bump redis from 3.5.3 to 4.5.3

Bumps [redis](https://github.com/redis/redis-py) from 3.5.3 to 4.5.3.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](https://github.com/redis/redis-py/compare/3.5.3...v4.5.3)

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

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

requirements.txt

@@ -1,2 +1,2 @@
-redis==3.5.3
+redis==4.5.3
 requests==2.22.0