Ligature not triggered on squiggly arrow

[evacchi]

This is an oddly specific issue, and just a minor annoyance, but if I've understood correctly, it traces back to the syntax theme (see tonsky/FiraCode#63).

The issue is that ~> is not turned into its ligature when using Fira Code, which generally means it has been broken up into two tokens (e.g., because of spans).

Is it possible to make it so that ~> characters are consecutive so that the ligature may trigger ?