Bump starlette from 0.36.3 to 0.40.0 in /fastapi

Bumps [starlette](https://github.com/encode/starlette) from 0.36.3 to 0.40.0.
- [Release notes](https://github.com/encode/starlette/releases)
- [Changelog](https://github.com/encode/starlette/blob/master/docs/release-notes.md)
- [Commits](encode/starlette@0.36.3...0.40.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

fastapi/requirements.txt

@@ -91,7 +91,7 @@ six==1.16.0
     # via python-dateutil
 sniffio==1.3.0
     # via anyio
-starlette==0.36.3
+starlette==0.40.0
     # via
     #   fastapi
     #   okdata-aws