Bump fastapi from 0.78.0 to 0.109.1 in /backend

Bumps [fastapi](https://github.com/tiangolo/fastapi) from 0.78.0 to 0.109.1.
- [Release notes](https://github.com/tiangolo/fastapi/releases)
- [Commits](fastapi/fastapi@0.78.0...0.109.1)

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

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Author: dependabot[bot]

backend/poetry.lock

@@ -32,7 +32,7 @@ dynaconf = "^3.1.7"
 httpx = "^0.23.1"
 pydantic = "^1.9.1"
 fastapi-utils = "^0.2.1"
-fastapi = "^0.78.0"
+fastapi = ">=0.78,<0.110"
 uvicorn = { extras = ["standard"], version = "^0.20.0" }
 pygraphviz = "^1.10"
 confluent-kafka = "^1.9.2"