chore: update fastapi requirement in /examples/fastapi

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@0.139.0...0.139.2)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-version: 0.139.2
  dependency-type: direct:production
...

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

Author: dependabot[bot]

examples/fastapi/pyproject.toml

@@ -3,7 +3,7 @@ name = "fastapi-example"
 version = "0"
 requires-python = ">=3.12"
 dependencies = [
-    "fastapi~=0.139.0",
+    "fastapi~=0.139.2",
     "uvicorn-hmr[all]",
 ]