Bump fastapi from 0.103.0 to 0.109.1 in /backend/requirements (#1043)

Bumps [fastapi](https://github.com/tiangolo/fastapi) from 0.103.0 to 0.109.1.
- [Release notes](https://github.com/tiangolo/fastapi/releases)
- [Commits](https://github.com/tiangolo/fastapi/compare/0.103.0...0.109.1)

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

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

backend/requirements/default.txt

@@ -6,7 +6,7 @@ celery==5.3.4
 chardet==5.2.0
 dask==2023.8.1
 distributed==2023.8.1
-fastapi==0.103.0
+fastapi==0.109.1
 fastapi-users==11.0.0
 fastapi-users-db-sqlalchemy==5.0.0
 filelock==3.12.0

backend/requirements/model_server.txt

@@ -1,4 +1,4 @@
-fastapi==0.103.0
+fastapi==0.109.1
 pydantic==1.10.7
 safetensors==0.3.1
 sentence-transformers==2.2.2