chore(deps): Bump flask-cors from 3.0.10 to 6.0.0 in /backend

Bumps [flask-cors](https://github.com/corydolphin/flask-cors) from 3.0.10 to 6.0.0.
- [Release notes](https://github.com/corydolphin/flask-cors/releases)
- [Changelog](https://github.com/corydolphin/flask-cors/blob/main/CHANGELOG.md)
- [Commits](corydolphin/flask-cors@3.0.10...6.0.0)

---
updated-dependencies:
- dependency-name: flask-cors
  dependency-version: 6.0.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

backend/requirements.txt

@@ -1,7 +1,7 @@
 Flask==2.2.5
 Flask-RESTful==0.3.9
 Flask-HTTPAuth==4.7.0
-Flask-Cors==3.0.10
+Flask-Cors==6.0.0
 Flask-Login==0.6.2
 requests==2.32.4
 gunicorn==23.0.0