`set heading(bookmarked: false)` doesn't work

[spidersouris]

Description of Issue

Using set heading(bookmarked: false) to hide bookmarks in the output PDF document does not work.

Minimal Example

#import "@preview/touying:0.4.2": *

#let s = themes.default.register()
#let (init, slides) = utils.methods(s)
#show: init

#set heading(bookmarked: false, outlined: false)

#let (slide, empty-slide) = utils.slides(s)
#show: slides

= Section

== Title 1

#slide[a slide]

== Title 2

#slide[another slide]

#slide[another slide]

= Section 2

== Title 3

#slide[yet another slide]

Current Behavior

Headings appear as bookmarks in the PDF.

Expected Behavior

Headings should not appear when setting set heading(bookmarked: false).

Related Issues

32, #58