Ace widget cannot be disabled

[MarcSkovMadsen]

Panel 0.10.2
Bokeh 2.2.3

Description of expected behavior and the observed behavior

The Controls section of the Ace widget shows the disabled parameter. But if I disable it I can still enter new text.

I.e. disabled does not work.

Complete, minimal, self-contained example code that reproduces the issue

from panel import widgets as pnw

py_code = """import sys"""
component = pnw.Ace(
    value=py_code,
    sizing_mode="stretch_width",
    language="python",
    theme="tomorrow_night",
    disabled=True,
    height=300,
)

component.servable()

[philippjfr]

Thanks! Please make the issue title as specific as possible.