build(deps): bump gunicorn from 20.0.4 to 20.1.0 in /backend (#862)

Bumps [gunicorn](https://github.com/benoitc/gunicorn) from 20.0.4 to 20.1.0.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@20.0.4...20.1.0)

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

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

Author: dependabot[bot]

backend/requirements.txt

@@ -6,7 +6,7 @@ Flask==1.1.2
 Flask-Cors==3.0.10
 flask-talisman==0.7.0
 google-cloud-storage==1.36.2
-gunicorn==20.0.4
+gunicorn==20.1.0
 python-dateutil==2.8.1
 pytoml==0.1.21
 redis==3.5.3