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

### 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: https://github.com/angular/components/pull/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

Start with the CDK listbox example `Listbox with forms validation` in the Angular Material documentation and reproduce the issue by selecting `Rat`, then clicking the scrollbar twice. Compare the behavior with the related menu change in PR 30249. Done means scrollbar clicks continue normal scrolling without jumping to the top, including after a value is selected.

Written by the indexing model from the issue text.