OSV-2023-739 UNKNOWN READ in OT::glyph_variations_t::create_from_glyphs_var_data

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=61724 Crash type: UNKNOWN READ Crash state: OT::glyphvariationst::createfromglyphsvardata OT::gvar::decompileglyphvariations OT::gvar::instantiate...