Update fastapi requirement from ~=0.115.8 to ~=0.115.11

Updates the requirements on [fastapi](https://github.com/fastapi/fastapi) to permit the latest version.
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](fastapi/fastapi@0.115.8...0.115.11)

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

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -1,4 +1,4 @@
-fastapi~=0.115.8
+fastapi~=0.115.11
 uvicorn[standard]~=0.34.0
 sqlalchemy[asyncio]==2.0.37
 asyncpg~=0.30.0