v5.9.4

What's Changed

• Bump webpack-dev-middleware from 5.3.3 to 5.3.4 by @dependabot in #1413
• Bump express from 4.18.2 to 4.19.2 by @dependabot in #1415
• Dev/5.9 by @takayukister in #1418
• Dev/5.9 by @takayukister in #1420

Full Changelog: v5.9.3...v5.9.4