build: bump fastapi from 0.115.6 to 0.115.8 in /App

Bumps [fastapi](https://github.com/fastapi/fastapi) from 0.115.6 to 0.115.8.
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](fastapi/fastapi@0.115.6...0.115.8)

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

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

Author: dependabot[bot]

App/requirements.txt

@@ -15,5 +15,5 @@ azure-cosmos
 azure-identity
 azure-mgmt-resource
 aiohttp
-fastapi==0.115.6
+fastapi==0.115.8
 httpx==0.28.0