Bump redis from 6.3.0 to 6.4.0 in /flowmachine

Bumps [redis](https://github.com/redis/redis-py) from 6.3.0 to 6.4.0.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](redis/redis-py@v6.3.0...v6.4.0)

---
updated-dependencies:
- dependency-name: redis
  dependency-version: 6.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]