exo: upgrade 4.20.0 -> 4.21.0

exo is deprecated in favor of libxfce4ui and libxfce4util as of
development version 4.21.0. The last stable release before archiving
the repository will be 4.22.0. See
https://gitlab.xfce.org/xfce/exo/-/merge_requests/87
and the links it contains for details.

- Update copyright year
- Deprecate exo-job and exo-simple-job
- Deprecate binaries
- Deprecate exo-tree-view
- Deprecate exo-icon-chooser-dialog and friends
- Deprecate exo-gtk-extensions
- Deprecate exo-gdk-pixbuf-extensions
- Deprecate exo-execute
- I18n: Update po/LINGUAS list
- Properly check iterator before usage (#124)
- Fix code style
- exo-tree-view: Allow Ctrl+Shift+Click in single click mode
- Translation Updates:
  Albanian, Catalan, Danish, Estonian, Polish, Portuguese, Romanian,
  Russian, Slovak, Slovenian, Venetian

Signed-off-by: Jason Schonberg <schonm@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-xfce/recipes-xfce/exo/exo_4.21.0.bb

@@ -15,7 +15,7 @@ SRC_URI += " \
     file://exo-no-tests-0.8.patch \
 "
 
-SRC_URI[sha256sum] = "4277f799245f1efde01cd917fd538ba6b12cf91c9f8a73fe2035fd5456ec078d"
+SRC_URI[sha256sum] = "26f85ca2db3bcf99d8b8af28b0d565b0186ccc3d2ed4a5ba315f6a589b8bc2c9"
 
 # Note: python bindings did not work in oe-dev and are about to be moved to
 # pyxfce see http://comments.gmane.org/gmane.comp.desktop.xfce.devel.version4/19560