Bump flask-cors from 5.0.0 to 6.0.0 in /load_testing (#539)

Bumps [flask-cors](https://github.com/corydolphin/flask-cors) from 5.0.0 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@5.0.0...6.0.0)

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

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

Author: dependabot[bot]

load_testing/requirements-dev.txt

@@ -5,7 +5,7 @@ charset-normalizer==3.3.2
 click==8.1.7
 ConfigArgParse==1.7
 Flask==3.0.3
-Flask-Cors==5.0.0
+Flask-Cors==6.0.0
 Flask-Login==0.6.3
 gevent==24.2.1
 geventhttpclient==2.3.1