Vaadin 24: HeightByRowsIT integration tests fail (testOpenWithItemsDefaultSize)

### Describe the bug

testOpenWithItemsDefaultSize: expected:<10> but was:<9>

### Expected behavior

_No response_

### Minimal reproducible example

_No response_

### Add-on Version

2.0.0-SNAPSHOT

### Vaadin Version

24.8.14

### Additional information

_No response_