build(deps): bump fakeredis from 1.5.2 to 1.6.0 in /backend (#1062)

Bumps [fakeredis](https://github.com/jamesls/fakeredis) from 1.5.2 to 1.6.0.
- [Release notes](https://github.com/jamesls/fakeredis/releases)
- [Commits](jamesls/fakeredis@1.5.2...1.6.0)

---
updated-dependencies:
- dependency-name: fakeredis
  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>

Author: dependabot[bot]

backend/requirements-dev.txt

@@ -1,4 +1,4 @@
-fakeredis==1.5.2
+fakeredis==1.6.0
 pre-commit==2.14.1
 pytest==6.2.4
 pytest-responses==0.5.0

backend/requirements.txt

@@ -1,7 +1,7 @@
 -e ../tools #egg=code-coverage-tools
 connexion==2.9.0
 datadog==0.42.0
-fakeredis==1.5.2
+fakeredis==1.6.0
 Flask==1.1.2
 Flask-Cors==3.0.10
 flask-talisman==0.8.1