Viewport scrollbar gets yanked to bottom of notebook

[ibdafna]

In a collaborative session with two users or more, when a user executes a code cell which, based on some interval, appends stdout content to the cell output area, the scrollbar of the users who did not execute the code gets yanked to the bottom of the page.

jupyter_collaboration==2.1.1
jupyterlab==4.1.5
pycrdt==0.8.23
pycrdt-websocket==0.13.4

[davidbrochart]

cc @afshin for awareness.