Update to Uvicorn 0.23.2

This commit will update/upgrade to Uvicorn 0.23.2.
User-facing
[changes](encode/uvicorn@0.22.0...0.23.2)
since 0.22.0 include dropping support for Python 3.7, switching to a
vendored copy of `asgiref.typing` at `uvicorn._types`, and a small scope
change in `uvicorn.middleware.proxy_headers.ProxyHeadersMiddleware`.

pyproject.toml

@@ -22,7 +22,7 @@ classifiers = [
 ]
 dependencies = [
   "gunicorn==20.1.0",
-  "uvicorn==0.22.0",
+  "uvicorn==0.23.2",
 ]
 description = "Docker images and utilities to power your Python APIs and help you ship faster."
 dynamic = ["version"]