The new build process associated with Bug 20168 adds a few new generated CSS files, opac-rtl.css, print-rtl.css, and sco-rtl.css. These files should be added by the RM to be tracked in git just like opac.css is.
I pushed a follow-up for bug 20168. However, did you see that there is a koha-tmpl/intranet-tmpl/prog/css/staff-global-rtl.css file that is generated by yarn build?
(In reply to Jonathan Druart from comment #1) > However, did you see that there is a > koha-tmpl/intranet-tmpl/prog/css/staff-global-rtl.css file that is generated > by yarn build? This issue is now Bug 27072