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

docs_src/debugging/tutorial001_py310.py

@@ -0,0 +1,15 @@
+import uvicorn
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/")
+def root():
+    a = "a"
+    b = "b" + a
+    return {"hello world": b}
+
+
+if __name__ == "__main__":
+    uvicorn.run(app, host="0.0.0.0", port=8000)