incompatible with flask 2 and async

It seems that flask-debugtoolbar is incompatible with flask 2 async endpoints.

Repro:

Run this flask project (app.py) and hit /data to trigger an async call - which works.

Then uncomment the line enabling the DebugToolbarExtension and we get an exception.

import asyncio
from flask import Flask
from flask import render_template
from icecream import ic
from flask_debugtoolbar import DebugToolbarExtension

app = Flask(__name__)

app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 0
app.config['JSON_SORT_KEYS'] = False
app.secret_key = 'super secret key'

# flask debug toolbar - https://flask-debugtoolbar.readthedocs.io/en/latest/index.html#configuration
app.debug = True
app.config['DEBUG_TB_INTERCEPT_REDIRECTS'] = False
app.config['DEBUG_TB_TEMPLATE_EDITOR_ENABLED'] = True
# toolbar = DebugToolbarExtension(app)  # <<<< UNCOMMENT THIS AND WATCH IT CRASH

@app.route('/')
def root():
    return "hi"


async def async_get_data():
    ic('in async function')
    await asyncio.sleep(2)
    ic('out of async function')
    return 'Done!'


@app.route("/data")
async def get_data():
    data = await async_get_data()
    return data

Start with the app.py reproduction: run the Flask project, enable DebugToolbarExtension, and request /data to capture the exception. Trace the toolbar path involved in async endpoints; done when the example works with the toolbar enabled and the regression is covered by an appropriate test.