📝 Update source examples and docs from Python 3.9 to 3.10 (#14900)

docs_src/path_params/tutorial003_py310.py

@@ -0,0 +1,13 @@
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/users/me")
+async def read_user_me():
+    return {"user_id": "the current user"}
+
+
+@app.get("/users/{user_id}")
+async def read_user(user_id: str):
+    return {"user_id": user_id}