[NTG-context] [font-syn.lua] remove call to fontloader.to_table()

Hi all, calling fontloader.to_table() appears to be redundant when extracting font names, see the attached patch. On my system I measured 42 (patched) vs 59 (vanilla) seconds for rebuilding the entire index: mtxrun --script fonts --reload --force The resulting index is -- except for the uuid, naturally -- identical in both cases. Best, Philipp