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

Angular Material のドキュメントにある CDK のリストボックス例 `Listbox with forms validation` から始め、`Rat` を選択してからスクロールバーを 2 回クリックして問題を再現します。PR 30249 の関連するメニュー変更と動作を比較します。値を選択した後も、スクロールバーのクリックで通常どおりスクロールが続き、先頭にジャンプしなければ完了です。

索引モデルが issue の本文から書いたものです。