v4.0.0

What's Changed

• Bump rack from 2.2.6.4 to 2.2.8.1 by @dependabot in #141
• Bump nokogiri from 1.16.2 to 1.16.5 by @dependabot in #142
• Bump rexml from 3.2.5 to 3.3.3 by @dependabot in #144
• Bump rexml from 3.3.3 to 3.3.6 by @dependabot in #145
• Bump rexml from 3.3.6 to 3.3.9 by @dependabot in #146
• use 4.0 packaging by @johrstrom in #147

Full Changelog: v3.0.5...v4.0.0