[gnome-shell-extensions] extensions: Remove horizontal-workspaces extension

[Marge Bot <marge-bot src gnome org>]

commit d7c8a5d193553f8d82616ed57ab9c28d5a6734ef
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Jan 29 16:57:16 2021 +0100

    extensions: Remove horizontal-workspaces extension
    
    Workspaces are now horizontal by default, so we don't need to change
    the layout for classic mode anymore.
    
    That was the only reason why the extension was added, so it has now
    outlived its usefulness.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/158>

 extensions/horizontal-workspaces/extension.js     | 38 -----------------------
 extensions/horizontal-workspaces/meson.build      |  5 ---
 extensions/horizontal-workspaces/metadata.json.in | 10 ------
 extensions/horizontal-workspaces/stylesheet.css   |  1 -
 meson.build                                       |  1 -
 5 files changed, 55 deletions(-)
---
diff --git a/meson.build b/meson.build
index 90b617f..d34cfd4 100644
--- a/meson.build
+++ b/meson.build
@@ -32,7 +32,6 @@ uuid_suffix = '@gnome-shell-extensions.gcampax.github.com'
 
 classic_extensions = [
   'apps-menu',
-  'horizontal-workspaces',
   'places-menu',
   'launch-new-instance',
   'window-list'