Font size combo boxes in the Preferences window are misaligned on macOS

[processing-bot]

Created by: benfry

So ugly!

But it's a Java bug, which has been opened since 2017:
https://bugs.openjdk.java.net/browse/JDK-8179076

We could make it not editable, or add an option like "Custom Size…" at the bottom of the menu, which could open up a window, but yech… what a mess.