gsk: cache sequentially requested hinted fonts
When getting the hinted version of fonts, they often come in sequentially. This helps reduce overhead in many sequential gtk_text_node_new() on with fractional scaling as you see from GtkSourceView.
When getting the hinted version of fonts, they often come in sequentially. This helps reduce overhead in many sequential gtk_text_node_new() on with fractional scaling as you see from GtkSourceView.