[css-writing-modes] Remove ''use-glyph-orientation'' from at risk as the value itself was removced

Author: kojiishi

css-writing-modes/Overview.bs

@@ -17,7 +17,6 @@ Former Editor: Paul Nelson, Microsoft, paulnel@microsoft.com
 Former Editor: Michel Suignard, Microsoft, michelsu@microsoft.com
 Abstract: CSS Writing Modes Level 3 defines CSS support for various international writing modes, such as left-to-right (e.g. Latin or Indic), right-to-left (e.g. Hebrew or Arabic), bidirectional (e.g. mixed Latin and Arabic) and vertical (e.g. Asian scripts).
 At Risk: The ''sideways-lr'' and ''sideways-rl'' of 'writing-mode'
-At Risk: The ''use-glyph-orientation'' of 'text-orientation'
 At Risk: The ''digits'' value of 'text-combine-upright'.
 At Risk: The look-ahead/look-behind sequencing rules for 'text-combine-upright'.
 At Risk: <a href="#auto-multicol">Automatic multi-column behavior</a> of orthogonal flows.