desktop: gimp-data-extras AppStream was moved to the appropriate repo.

See the commit 28467cb on the gimp-data-extras repo where I moved this
data in. Not sure why this metadata file was ever pushed to the main
repo as it is obviously for the data-extras package (or else I am
missing some information!).

The old 2017 report where it was originally added:
https://bugzilla.gnome.org/show_bug.cgi?id=763398

configure.ac

@@ -2671,7 +2671,7 @@ if test "x$with_appdata_test" != "xno"; then
     have_appstreamcli="no (appstreamcli not found)"
   fi
 fi
-AM_CONDITIONAL(HAVE_APPSTREAM_UTIL, test "x$have_appstreamcli" = "xyes")
+AM_CONDITIONAL(HAVE_APPSTREAMCLI, test "x$have_appstreamcli" = "xyes")
 if test "x$have_appstreamcli" = "xyes"; then
   have_appstreamcli="yes (this test requires network access; --without-appdata-test to disable)"
 fi
@@ -3212,7 +3212,6 @@ data/tool-presets/Paint/Makefile
 data/tool-presets/Selection/Makefile
 data/tool-presets/Sketch/Makefile
 desktop/Makefile
-desktop/org.gimp.GIMP.data_extras.metainfo.xml.in
 desktop/gimp.desktop.in
 desktop/org.gimp.GIMP.appdata.xml.in
 desktop/test-appdata.sh

desktop/.gitignore

@@ -4,7 +4,5 @@
 /org.gimp.GIMP.appdata.xml
 /gimp.desktop.in
 /gimp.desktop
-/org.gimp.GIMP.data_extras.metainfo.xml.in
-/org.gimp.GIMP.data_extras.metainfo.xml
 /test-appdata.sh
 /.thumbnails

desktop/Makefile.am

@@ -6,8 +6,7 @@ desktop_in_files = \
 desktop_files = $(desktop_in_files:.desktop.in.in=.desktop)
 
 appstream_in_files = \
-	org.gimp.GIMP.appdata.xml.in	\
+	org.gimp.GIMP.appdata.xml.in
-	org.gimp.GIMP.data_extras.metainfo.xml.in
 
 appstream_files = $(appstream_in_files:.xml.in=.xml)
 
@@ -87,7 +86,7 @@ TESTS_ENVIRONMENT = \
 	GIMP_TESTING_ABS_TOP_BUILDDIR=@abs_top_builddir@
 TESTS =
 
-if HAVE_APPSTREAM_UTIL
+if HAVE_APPSTREAMCLI
 TESTS += test-appdata.sh
 endif
 

desktop/meson.build

@@ -71,28 +71,6 @@ appdatafile = custom_target(appdatafilename,
   install_dir: get_option('datadir') / 'metainfo',
 )
 
-metainfofilename = 'org.gimp.GIMP.data_extras.metainfo.xml'
-metainfofilein = configure_file(
-  input : metainfofilename+'.in.in',
-  output: metainfofilename+'.in',
-  configuration: desktop_conf,
-)
-metainfofile = custom_target(metainfofilename,
-  input : [ metainfofilein, ],
-  output: [ metainfofilename, ],
-  command: [
-    intltool_merge,
-    po_dir,
-    '@INPUT@',
-    '@OUTPUT@',
-    '--xml-style',
-    '--utf8',
-    '--cache=' + '@OUTDIR@' / 'intltool-merge-cache',
-  ],
-  install: true,
-  install_dir: get_option('datadir') / 'metainfo',
-)
-
 if desktop_validate.found()
   test('validate-desktop',
     desktop_validate,
@@ -110,13 +88,4 @@ if appstreamcli.found()
     ],
     suite: 'desktop',
   )
-
-  test('metainfo_file',
-    appstreamcli,
-    args: [ 'validate', metainfofile ],
-    env: [
-      'GIMP_TESTING_ABS_TOP_BUILDDIR=' + meson.build_root(),
-    ],
-    suite: 'desktop',
-  )
 endif

desktop/org.gimp.GIMP.data_extras.metainfo.xml.in.in

@@ -1,13 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!-- Copyright 2015 Jiri Eischmann <eischmann@redhat.com> -->
-<component type="addon">
-  <id>org.gimp.GIMP.data_extras</id>
-  <extends>org.gimp.GIMP</extends>
-  <_name>Extra files for GIMP</_name>
-  <_summary>Patterns, gradients, and other extra files for GIMP</_summary>
-  <url type="homepage">https://www.gimp.org/</url>
-  <url type="bugtracker">@BUG_REPORT_URL@</url>
-  <metadata_license>CC0-1.0</metadata_license>
-  <project_license>GPL-3.0+</project_license>
-  <update_contact>alexandre.prokoudine@gmail.com</update_contact>
-</component>

desktop/test-appdata.sh.in

@@ -3,7 +3,6 @@
 # TODO: use validate-strict when the last errors for a strict validation
 # are fixed.
 appstreamcli validate ${GIMP_TESTING_ABS_TOP_BUILDDIR}/desktop/org.gimp.GIMP.appdata.xml && \
-appstreamcli validate ${GIMP_TESTING_ABS_TOP_BUILDDIR}/desktop/org.gimp.GIMP.data_extras.metainfo.xml && \
 if [ $(expr @GIMP_MICRO_VERSION@ % 2) = 0 ]; then
   grep TODO ${GIMP_TESTING_ABS_TOP_BUILDDIR}/desktop/org.gimp.GIMP.appdata.xml
   if [ $? = 0 ]; then

po/POTFILES.in

@@ -4,7 +4,6 @@
 [encoding: UTF-8]
 
 desktop/org.gimp.GIMP.appdata.xml.in.in
-desktop/org.gimp.GIMP.data_extras.metainfo.xml.in.in
 desktop/gimp.desktop.in.in
 
 app/about.h

po/POTFILES.skip

@@ -3,7 +3,6 @@ build/windows/installer/lang/setup.isl.in
 data/tags/gimp-tags-default.xml.in
 data/tips/gimp-tips.xml.in
 desktop/org.gimp.GIMP.appdata.xml.in
-desktop/org.gimp.GIMP.data_extras.metainfo.xml.in
 desktop/gimp.desktop.in
 extensions
 libgimp