build(deps): update fastapi requirement from ~=0.115.2 to ~=0.115.5

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@0.115.2...0.115.5)

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

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

requirements.txt

@@ -9,5 +9,5 @@ sentencepiece~=0.2.0
 setuptools~=75.1.0
 huggingface-hub~=0.25.2
 transformers~=4.46.2
-fastapi~=0.115.2
+fastapi~=0.115.5
 uvicorn~=0.32.0