QWindowsFontEngineDirectWrite ignores QFont::NoAntialias flag

When HiDPI is on, Qt forces to draw text using QWindowsFontEngineDirectWrite. If the text can be drawn using the glyph cache, QWindowsFontEngineDirectWrite::imageForGlyph() is called to render the glyph. But NoAntialias flag is ignored.

When using GDI font engine (HiDPI is off), NONANTIALIASED_QUALITY is set: https://github.com/qt/qtbase/blob/5.15.2/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase.cpp#L1800-L1801

When using DirectWrite font engine (HiDPI is on), there is no code to turn off antialiasing (DWRITE_RENDERING_MODE_ALIASED?): https://github.com/qt/qtbase/blob/5.15.2/src/platformsupport/fontdatabases/windows/qwindowsfontenginedirectwrite.cpp#L196-L203

This only happens when drawing small texts with the glyph cache.