Bump fastapi from 0.104.1 to 0.109.1 in /backend (#687)

Bumps [fastapi](https://github.com/tiangolo/fastapi) from 0.104.1 to 0.109.1.
- [Release notes](https://github.com/tiangolo/fastapi/releases)
- [Commits](https://github.com/tiangolo/fastapi/compare/0.104.1...0.109.1)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-type: direct:production
...

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backend/pyproject.toml

@@ -7,7 +7,7 @@ authors = ["Admin <admin@example.com>"]
 [tool.poetry.dependencies]
 python = "^3.10"
 uvicorn = {extras = ["standard"], version = "^0.24.0.post1"}
-fastapi = "^0.104.1"
+fastapi = "^0.109.1"
 python-multipart = "^0.0.6"
 email-validator = "^2.1.0.post1"
 celery = "^5.3.5"