build(deps): update asciidoctor-pdf requirement from 2.3.17 to 2.3.21

[dependabot]

Updates the requirements on asciidoctor-pdf to permit the latest version.

Release notes

Sourced from asciidoctor-pdf's releases.

v2.3.21

This is a small, but mighty patch release in the 2.3.x release line to address some AsciiDoc compliance issues and improve the overall usability of the software.

In terms of AsciiDoc compliance, the float-group enclosure is now honored for floats and see and see-also associations on index terms are now included in the index. In terms of usability, the pdf-fontsdir attribute has a more sensible default so it doesn't need to be set when using custom fonts in a custom theme. When text cannot be parsed, shy hyphens are removed to make the text easier to find in the source document.

Distribution

• RubyGem (asciidoctor-pdf)

Changelog

Improvements

• remove shy hyphens from text in log message when formatted text cannot be parsed (#2599)
• clear float box if next block falls outside of flaot group (#2596)
• resolve fonts relative to theme dir before GEM_FONTS_DIR if pdf-fontsdir not specified (#2349)
• add see and see-also associations on index terms to index (#2527)

Release meta

Released on: 2025-10-07 Released by: @​mojavelinux Release beer: Oktoberfest by Athletic Brewing Company

Logs: resolved issues | source diff | gem diff

Credits

A very special thanks to all the awesome supporters of the Asciidoctor OpenCollective campaign, who provide critical funding for the ongoing development of this project.

Commits

• b305f37 release 2.3.21
• 422adf5 backport fix for #2527 add see and see-also associations on index terms to index
• 3218b22 wrap name in FormattedString inside index catalog; only use store_term
• e0c1411 rename pagenum_fragment variable to link_fragment for clarity and future use
• ff92561 backport fix for #2349 resolve fonts relative to theme dir before GEM_FONTS_D...
• 769576b backport fix for #2595 document the columns key for defining running content ...
• f4b1c50 backport fix for #2596 clear float box if next block falls outside of float g...
• ab4817a change code to make way for implementing support for float-group
• a500f62 backport fix for #2599 remove shy hyphens from text in log message when forma...
• 7a0701a add test to verify foreground image supports PNG transparency
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot show <dependency name> ignore conditions will show all of the ignore conditions of the specified dependency
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

[dependabot]

Superseded by #27.