Bump redis from 5.0.7 to 5.1.1 (#4332)

Bumps [redis](https://github.com/redis/redis-py) from 5.0.7 to 5.1.1.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](redis/redis-py@v5.0.7...v5.1.1)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -311,7 +311,7 @@ pyvips==2.2.3
     # via large-image-source-vips
 rcssmin==1.1.1
     # via django-compressor
-redis==5.0.7
+redis==5.1.1
     # via geotrek (setup.py)
 reportlab==4.1.0
     # via