Bump redis from 5.2.0 to 5.2.1 in /server

Bumps [redis](https://github.com/redis/redis-py) from 5.2.0 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@v5.2.0...v5.2.1)

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

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

server/requirements.txt

@@ -26,7 +26,7 @@ pdfrw==0.4
 pyjwt==2.10.*
 python-dateutil==2.9.*
 pytz
-redis==5.2.0
+redis==5.2.1
 reportlab==4.2.*
 requests==2.32.*
 sentry-sdk==2.19.*