Bump discord-webhook from 0.15.0 to 1.1.0 in /backend

Bumps [discord-webhook](https://github.com/lovvskillz/python-discord-webhook) from 0.15.0 to 1.1.0.
- [Release notes](https://github.com/lovvskillz/python-discord-webhook/releases)
- [Changelog](https://github.com/lovvskillz/python-discord-webhook/blob/master/CHANGES.md)
- [Commits](https://github.com/lovvskillz/python-discord-webhook/compare/0.15.0...1.1.0)

---
updated-dependencies:
- dependency-name: discord-webhook
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

backend/requirements.txt

@@ -6,5 +6,5 @@ python-socketio==5.7.2
 six==1.16.0
 pytest==7.2.1
 requests==2.28.2
-discord-webhook==0.15.0
+discord-webhook==1.1.0
 datadog==0.44.0