data: Remove old GConf migration files

The migration happened in GNOME 3.6 over 9 years ago. The chances
that someone migrates from 3.0.x or 3.2.x to 41 are very much zero.
And if it were to happen, it wouldn't work anyway, because we stopped
using a separate overrides schema.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1890>

data/gnome-shell-overrides.convert

@@ -1,4 +0,0 @@
-[org.gnome.shell.overrides]
-attach-modal-dialogs = /desktop/gnome/shell/windows/attach_modal_dialogs
-edge-tiling = /desktop/gnome/shell/windows/edge_tiling
-workspaces-only-on-primary = /desktop/gnome/shell/windows/workspaces_only_on_primary

data/meson.build

@@ -127,5 +127,3 @@ custom_target('compile-schemas',
   output: 'gschemas.compiled',
   command: [find_program('glib-compile-schemas'), meson.current_build_dir()],
   build_by_default: true)
-
-install_data('gnome-shell-overrides.convert', install_dir: convertdir)

meson.build

@@ -54,7 +54,6 @@ pkgdatadir = join_paths(datadir, meson.project_name())
 pkglibdir = join_paths(libdir, meson.project_name())
 
 autostartdir = join_paths(sysconfdir, 'xdg', 'autostart')
-convertdir = join_paths(datadir, 'GConf', 'gsettings')
 desktopdir = join_paths(datadir, 'applications')
 icondir = join_paths(datadir, 'icons')
 ifacedir = join_paths(datadir, 'dbus-1', 'interfaces')