Update fastapi requirement from ~=0.103.2 to ~=0.104.0 in /code/function

Updates the requirements on [fastapi](https://github.com/tiangolo/fastapi) to permit the latest version.
- [Release notes](https://github.com/tiangolo/fastapi/releases)
- [Commits](fastapi/fastapi@0.103.2...0.104.0)

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

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

Author: dependabot[bot]

code/function/requirements.txt

@@ -4,7 +4,7 @@
 
 # azure-identity~=1.13.0
 azure-functions~=1.17.0
-fastapi~=0.103.2
+fastapi~=0.104.0
 pydantic-settings~=2.0.3
 aiohttp~=3.8.6
 opentelemetry-instrumentation-fastapi==0.41b0