4.21.1 - Update copyright year - Add rust & xfwl4 deps - ci: Make cppcheck cfg prefix configurable - ci: scan-build related updates after switching to ubuntu 26.04 - ci: gcc-analyzer related updates after switching to ubuntu 26.04 - ci: Add cppcheck job - Upgrade xfce-build container to Ubuntu 26.04 LTS - xfce-build: add libxkbregistry-dev to container - Update docker/docker-dind images for CI - doc: Update developer.xfce.org index - gst-plugin-gtk: New dependency for video wallpapers in xfdesktop - meson: Fix typo in optimization level - ci: Add docbook-xml to CI build - ci: Add libpam0g-dev to CI build - ci: Add libsystemd-dev, xmlto to CI build - ci: Add libgexiv2-dev to CI build