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

docs_src/path_params/tutorial004_py310.py

@@ -0,0 +1,8 @@
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/files/{file_path:path}")
+async def read_file(file_path: str):
+    return {"file_path": file_path}