ANNOUNCE: xfce4-dev-tools 4.21.0 released

[Gaël Bonithon]

xfce4-dev-tools 4.21.0 is now available for download from
  
  https://archive.xfce.org/src/xfce/xfce4-dev-tools/4.21/xfce4-dev-tools-4.21.0.tar.bz2
  https://archive.xfce.org/src/xfce/xfce4-dev-tools/4.21/xfce4-dev-tools-4.21.0.tar.bz2?sha1
  https://archive.xfce.org/src/xfce/xfce4-dev-tools/4.21/xfce4-dev-tools-4.21.0.tar.bz2?sha256


What is xfce4-dev-tools?
========================

The Xfce Development Tools are a set of scripts and m4/autoconf macros
that ease build system maintenance.

Website: 
  https://docs.xfce.org/xfce/xfce4-dev-tools/start


Release notes for 4.21.0
========================
[Please note that this is a development release.]

- Update copyright year
- ci: Add python3-psutil to CI build
- ci: Add libasound2-dev and libsndio-dev to CI build
- ci: Add libapr1-dev and libaprutil1-dev to CI build
- ci: Add libaccountsservice-dev to CI build
- xfce-do-release: Add xfce-revision.h.in to tarball without REVISION
- ci: Update build_libs.sh after thunar dropped half its doc
- xfce-do-release: Copy extra source files to the working tree
- ci: Add libxnvctrl-dev to CI build
- ci: Be more verbose when copying docs
- Replace deprecated exo with libxfce4ui 4.21.0
- ci: Add libxpresent-dev to CI build
- meson-template: Add copyright year management
- Automate copyright year management
- Add libutempter-dev to CI build
- Add libqrencode-dev to CI build
- meson-template: Use SPDX license expression
- ci: Fix random pipefail in container build
- Add libpolkit-gobject-1-dev to CI build
- Review debug mode management in the meson template
- xfce-do-release: Prioritize meson for dev releases
- ci: Use same gtk-doc detection for container and project build
- ci: Prioritize meson for container build
- Add libcolord-dev to CI build
- Add xserver-xorg-input-libinput-dev to CI build
- ci: Support generated symbols file in meson builds
- Add libgladeui-dev to CI build
- Add -Wno-missing-field-initializers to meson template
- Add libcanberra-gtk3-dev to the build container
- ci: Use --auto-features=enabled in meson builds
- scripts: Complete visibility doc
- Build gtk-doc during meson dist if docs present
- xfce-do-release: Fix tarball path with meson