Bump redis from 5.1.1 to 5.2.1

Bumps [redis](https://github.com/redis/redis-py) from 5.1.1 to 5.2.1.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](redis/redis-py@v5.1.1...v5.2.1)

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

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

requirements.txt

@@ -3,6 +3,6 @@ Flask==3.0.0
 itsdangerous==2.2.0
 Jinja2==3.1.4
 MarkupSafe==2.1.1
-redis==5.1.1
+redis==5.2.1
 Werkzeug==3.0.6
 flask-babel