Cannot load and parse xsl urls for manpages

Package Information

• Package name: docbook-xsl
• Package version: 1.79.2-r10
• Alpine version: 3.21.0_alpha20240923
• Alpine architecture: x86_64, other arches affected

Summary

A few aports are failing to generate manpages on the 3.21 builders with the error:

ninja: job failed: /usr/bin/xsltproc --output man/glade-previewer.1 --stringparam man.output.quietly 1 --stringparam funcsynopsis.style ansi --stringparam man.th.extra1.suppress 1 --stringparam man.authors.section.enabled 0 --stringparam man.copyright.section.enabled 0 http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl ../man/glade-previewer.xml
I/O error : unsupported protocol: https
warning: failed to load external entity "http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl"
cannot parse http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl

The above error comes from community/glade (volatile log), others have a variation of the error via gtkdoc-mkhtml with xsl:import.

Initial testing seems to indicate the error may be related to a recent change in docbook-xsl, or its dependencies. An affected aport rebuilds successfully with docbook-xsl-1.79.2-r9, but fails on -r10 (starting with this version).