gnome-desktop: fix thumbnail generation on musl systems.

/etc/ld.so.cache doesn't exist on musl systems, which makes the bwrap
command fail. Users will have to remove the "failed generation" cache
from ~/.cache/thumbnails/fail/ for nautilus to reattempt thumbnail
generation of previously visited directories.

Upstream issue:
https://gitlab.gnome.org/GNOME/gnome-desktop/-/issues/117

Seems to be the direction upstream is moving in as well:
https://gitlab.gnome.org/GNOME/gnome-desktop/-/merge_requests/107

Fixes #29767.

srcpkgs/gnome-desktop/patches/thumbnail-bwrap-musl.patch

@@ -0,0 +1,13 @@
+diff --git libgnome-desktop/gnome-desktop-thumbnail-script.c libgnome-desktop/gnome-desktop-thumbnail-script.c
+index cfbbad0..efad40b 100644
+--- libgnome-desktop/gnome-desktop-thumbnail-script.c
++++ libgnome-desktop/gnome-desktop-thumbnail-script.c
+@@ -532,7 +532,7 @@ add_bwrap (GPtrArray   *array,
+   add_args (array,
+ 	    "bwrap",
+ 	    "--ro-bind", "/usr", "/usr",
+-	    "--ro-bind", "/etc/ld.so.cache", "/etc/ld.so.cache",
++	    "--ro-bind-try", "/etc/ld.so.cache", "/etc/ld.so.cache",
+ 	    NULL);
+ 
+   /* These directories might be symlinks into /usr/... */

srcpkgs/gnome-desktop/template

@@ -1,7 +1,7 @@
 # Template file for 'gnome-desktop'
 pkgname=gnome-desktop
 version=3.38.4
-revision=1
+revision=2
 build_style=meson
 build_helper="gir"
 configure_args="-Dgnome_distributor=VoidLinux -Dudev=enabled -Dsystemd=disabled