ConnectionAbortedError/asyncio.CancelledError when the page's loading is canceled by the user is not catchable.

The error ConnectionAbortedError is thrown if the page's loading is canceled. Using @app.errorhandler(ConnectionAbortedError) with an appropriate function is completely ignored. How do I handle (or just suppress) this error?

reproducible example:

from quart import Quart
from time import sleep
import asyncio

app = Quart(__name__)

@app.route('/')
async def hello():
    await asyncio.sleep(1)
    return 'Hello, world!'

if __name__ == '__main__':
    app.run()

reproduce the bug:
run the script. connect to localhost:5000. cancel the load when the page is loading.

traceback: https://pastebin.com/aueksHyg

this error should not be thrown (or there needs to be a way to catch it.)

Environment:

• Python version: 3.11.2
• Quart version: 0.18.4

Start by running the issue's Quart example with Python 3.11.2, canceling the request during asyncio.sleep, and examining the linked traceback. Trace how the canceled request reaches Quart's error handling and compare that path with @app.errorhandler(ConnectionAbortedError). Done means cancellation is either suppressed as intended or exposes a documented, usable handling path without an uncaught error.