bug(cdk-virtual-scroll-viewport): If there is not enough data without caching, the scrolling operation will be invalid.

### Is this a regression?

_No response_

### Description

If there is not enough data without caching, the scrolling operation will be invalid.

### Reproduction

StackBlitz link:https://stackblitz.com/edit/angular-sbfsdw?file=src%2Fapp%2Fapp.component.ts,src%2Fapp%2Fng-zorro-antd.module.ts,src%2Fapp%2Fapp.module.ts
Steps to reproduce:
1. If you scroll the mouse in the container, the scroll bar will always react, resulting in unsuccessful scrolling.
2. If you drag the scroll bar directly, you can basically scroll normally, and if the data length is in a certain interval, there will be obvious problems of unsuccessful scrolling.

The core code is as follows：
```
@Component({
selector: 'nz-demo-button-basic',
template: `

`,
styles: [
`
.example-viewport {
height: 600px;
width: 200px;
border: 1px solid black;
}

.example-item {
height: 250px;
border: 1px solid red;
}
`,
],
changeDetection: ChangeDetectionStrategy.OnPush,
})
export class NzDemoButtonBasicComponent {
// length 20000 scroll working
// length 20 scroll no working
items = Array.from({ length: 20 }).map((_, i) => `Item #${i}`);
}
```

### Expected Behavior

No matter the size of itemsize or the amount of data, the scrolling effect is normal.

### Actual Behavior

Unable to scroll up and down

### Environment

- Angular: 16+、18+
- CDK/Material: 16+、18+
- Browser(s):
- Operating System (e.g. Windows, macOS, Ubuntu):

Run the linked StackBlitz reproduction from src/app/app.component.ts with templateCacheSize set to 0 and a short items array. Start at the cdk-virtual-scroll-viewport behavior for insufficient data, then verify scrolling with different item counts and itemSize values. Done means mouse-wheel and scrollbar dragging both scroll normally regardless of data length.

由索引模型根据 Issue 内容生成。