bug(cdk/listbox): using scrollbar with mouse breaks

[spike-rabbit]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

When using the cdk listbox on a list that scrolls, the listbox and scroll position behaves weird if that scrollbar is operated with a mouse. The behavior gets worsed if a value is selected.
Operated by mouse means either:

• clicking on the little arrows in that scrollbar
  
• clicking on a blank space within that scrollbar
  

I think there was recently a similar issue in the menu: #30249

Reproduction

StackBlitz link: Also broken in your docs at https://material.angular.io/cdk/listbox/examples
Steps to reproduce:

1. Got to example Listbox with forms validation.
2. Select option Rat
3. Click the down arrow two times in the scrollbar / or two times at a blank location

Expected Behavior

It should just scroll normally.

Actual Behavior

First click scrolls, at second click it jumps back to the top.

Environment

• Angular: 19 / and the version your docs use
• CDK/Material: 19 / and the version your docs use
• Browser(s): Chrome
• Operating System (e.g. Windows, macOS, Ubuntu): Linux / Mac

[SergheiGurgurov]

took me a while to debug, it's a problem with the focus bouncing back between the listbox and it's children, which caused the selected item to scroll into view

i submitted a PR which stops the event from being forwarded to the children when it comes from a mouse interaction, which is the same way the bug on the cdk/menu was fixed

[spike-rabbit]

Thx a lot for this amazingly fast reaction