Bump fastapi from 0.115.0 to 0.115.2 in /backend (#77)

Bumps [fastapi](https://github.com/fastapi/fastapi) from 0.115.0 to 0.115.2.
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](fastapi/fastapi@0.115.0...0.115.2)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

backend/poetry.lock

@@ -8,7 +8,7 @@ packages = [{include = "quotes"}]
 
 [tool.poetry.dependencies]
 python = "^3.11"
-fastapi = "^0.115.0"
+fastapi = "^0.115.2"
 uvicorn = "^0.31.1"
 pydantic = "^2.9.2"
 pydantic-settings = "^2.5.2"