build(deps): bump google-cloud-storage from 2.18.2 to 3.2.0 in /backend (#2705)

---
updated-dependencies:
- dependency-name: google-cloud-storage
  dependency-version: 3.2.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

backend/requirements.txt

@@ -4,7 +4,7 @@ datadog==0.51.0
 Flask==2.2.3
 Flask-Cors==6.0.1
 flask-talisman==1.1.0
-google-cloud-storage==2.18.2
+google-cloud-storage==3.2.0
 gunicorn==23.0.0
 python-dateutil==2.9.0.post0
 pytoml==0.1.21