Release Expat 2.4.6

[hartwork]

Regular releases:

• Bump .so version info, document in change log
• Bump release version everywhere (including doc/reference.html)
• Fill release date (both change log and man page date)
• make distcheck source tarballs using ./distribute.sh
• Build Windows installer using AppVeyor CI — https://ci.appveyor.com/project/libexpat/libexpat/builds/42644750/artifacts
• Build Windows binaries zip file from installer
• SourceForge:
  • Upload Windows installer and binaries zip file
  • Upload source tarballs + .asc GPG signature files
  • Make one new source tarball default download for all but Windows
  • Make new binary zip file default download for Windows
• GitHub:
  • Create signed Git tag and push it
  • Create new release — https://github.com/libexpat/libexpat/releases/tag/R_2_4_6
  • Upload source tarballs + .asc GPG signature files
  • Upload Windows installer and binaries zip file
  • Close current milestone and create a follow-up one
• Website
  • Add news item — libexpat/libexpat.github.io@b38d311
  • Sync API documentation — libexpat/libexpat.github.io@d4e48ea
• Let the community know:
  • Mail Expat distro maintainers directly
  • Write to the xml-dev mailing list — http://lists.xml.org/archives/xml-dev/202202/msg00099.html
  • Blog about it at blog.hartwork.org — https://blog.hartwork.org/posts/expat-2-4-6-released/
    • Submit to Hacker News — https://news.ycombinator.com/item?id=30408400
  • Blog about it at xml.com — https://www.xml.com/news/2022-02-expat-246/
• Bump ebuild in Gentoo — gentoo/gentoo@d81dcbd

Related downstreams issues and pull requests:

• Packaging
  • Haiku — Please update Expat to 2.4.6 with a regression fix haikuports/haikuports#6645
  • NixOS — expat: 2.4.5 -> 2.4.6 NixOS/nixpkgs#161090
  • Spack — expat: Add latest release 2.4.6 with a regression fix spack/spack#29100