Bump aiohttp from 3.8.6 to 3.9.4 in /app/backend

Bumps [aiohttp](https://github.com/aio-libs/aiohttp) from 3.8.6 to 3.9.4.
- [Release notes](https://github.com/aio-libs/aiohttp/releases)
- [Changelog](https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst)
- [Commits](aio-libs/aiohttp@v3.8.6...v3.9.4)

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

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

app/backend/requirements.txt

@@ -4,7 +4,7 @@ langchain==0.1.20
 langchain_openai 
 tiktoken
 uvicorn[standard]==0.24.0.post1
-aiohttp==3.8.6
+aiohttp==3.9.4
 azure-monitor-opentelemetry==1.0.0b15
 opentelemetry-instrumentation-asgi==0.40b0
 opentelemetry-instrumentation-requests==0.40b0