Conditionally required entity reference fields do not get * to indicate required

I reproduced this issue on 4.x and 4.0.0-alpha5 and I did not find any problem after reproducing the issue.

Opened an MR with a fix for this. The issue is not really related to the autocomplete widget, but instead an autocomplete widget that accepts multiple values which is then automatically rendered inside a table (tabledrag). Specifically this fixes the issue in Claro. It may fix the issue in other themes as well, but since we can't control the markup of the table header (because that is up to the theme) I want to call out Claro specifically as the only theme I've tested this in.