Fix string and none in comparison

[quachpas]

No description provided.

[cschreib-ibex]

I am hitting this as well after migrating from v0.1.0; not sure what I am doing wrong.

#import "@preview/metro:0.3.0": unit, units, prefixes, qty, declare-unit

#declare-unit("mm", unit($prefixes.milli units.meter$))

#qty(0, "mm")

Workaround seems to be to remove the unit(...)

#import "@preview/metro:0.3.0": unit, units, prefixes, qty, declare-unit

#declare-unit("mm", $prefixes.milli units.meter$)

#qty(0, "mm")