Changes how we avoid problems with special tags inside <select> elements. Instead of complicating the rendering of <style> elements in all cases, now we just close special elements when they are embedded in <select> elements so no text under a <select> is interpreted as anything other than PCDATA.
This is a follow on to https://docs.google.com/document/d/11SoX296sMS0XoQiQbpxc5pNxSdbJKDJkm5BDv0zrX50/edit#heading=h.ff1sdefzjxrx and we recommend using it over v20211018.1.