gnu: gnome-shell: Update to 40.5.

Remove the theme patch that does not apply anymore because the CSS files have
been revamped.

* gnu/packages/patches/gnome-shell-CVE-2020-17489.patch: Remove it.
* gnu/packages/patches/gnome-shell-theme: Remove it.
* gnu/packages/patches/gnome-shell-disable-test.patch: Update it.
* gnu/local.mk (DIST_PATCH_DATA): Update it.
* gnu/packages/gnome.scm (gnome-shell): Update to 40.5.
[source]: Fix the URI. Update the patches. Remote the snippet.
[arguments]: Remove trailing #t.
<#:phases>: Add a 'skip-gtk-update-icon-cache phase. Remove the
'convert-logo-to-png phase. Remove the inkscape disallowed reference.
[native-inputs]: Remove inkscape. Add hicolor-icon-theme.
[inputs]: Add gtk and graphene.
[properties]: Remove it.

gnu/packages/patches/gnome-shell-disable-test.patch

@@ -1,17 +1,16 @@
 This test seems to require a D-Bus connection not available in the build
 environment.
 
-diff -ur /tmp/guix-build-gnome-shell-3.34.2.drv-0/gnome-shell-3.34.2/src/st/meson.build b/src/st/meson.build
---- /tmp/guix-build-gnome-shell-3.34.2.drv-0/gnome-shell-3.34.2/src/st/meson.build	1969-12-31 19:00:00.000000000 -0500
-+++ b/src/st/meson.build	2019-12-23 00:46:14.721198022 -0500
-@@ -132,18 +132,6 @@
+--- a/src/st/meson.build	2021-09-21 19:07:38.673049200 +0000
++++ b/src/st/meson.build	2021-09-26 18:23:38.461569826 +0000
+@@ -191,18 +191,6 @@
    sources: st_enums[1]
  )
  
 -test_theme = executable('test-theme',
 -  sources: 'test-theme.c',
 -  c_args: st_cflags,
--  dependencies: [mutter_dep, gtk_dep],
+-  dependencies: [mutter_dep, gtk_dep, libxml_dep],
 -  build_rpath: mutter_typelibdir,
 -  link_with: libst
 -)