Update to FastAPI 0.96

This commit will update/upgrade to FastAPI 0.96.
FastAPI 0.96 improves the performance of `create_cloned_field`,
which is used by FastAPI internally when instantiating API routes.

https://fastapi.tiangolo.com/release-notes/
fastapi/fastapi#8609

pyproject.toml

@@ -45,7 +45,7 @@ docs = [
   "mkdocs-material>=8,<9",
 ]
 fastapi = [
-  "fastapi>=0.95,<0.96",
+  "fastapi>=0.96,<0.97",
 ]
 starlette = [
   "starlette>=0.27,<0.28",