EuiComboBox shows scrollbars since update to 27.0.0

[timroes]

After the update from EUI 26.3.0 to 27.0.0 the EuiComboBox component started showing always scrollbars (no matter the amount of elements) and is for a few pixels scrollable, since the content slightly extends the container always (the following combobox has only 3 elements):

[chandlerprall]

Confirmed the issue in Chrome, Firefox, and Edge on MacOS. Issue comes from EuiComboBoxOptionsList's default value for rowHeight, looks like it needs to be changed to 29 instead of its current 27 - this change removes the scrollbar in the 3 mentioned browsers. Looks like the switch from react-virtualized to react-window caused some small pixel shifting.