Fix todos after moving css to frontend

app/assets/stylesheets/openproject.sass

@@ -1,34 +0,0 @@
-/*-- copyright
- * OpenProject is an open source project management software.
- * Copyright (C) 2012-2020 the OpenProject GmbH
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version 3.
- *
- * OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
- * Copyright (C) 2006-2013 Jean-Philippe Lang
- * Copyright (C) 2010-2013 the ChiliProject Team
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
- *
- * See docs/COPYRIGHT.rdoc for more details.  ++
- */
-
-// Todo for task #33508
-
-// Enable asset pipeline for Bourbon mixins (e.g. +font-face)
-// @see http://bourbon.io/docs/#asset-pipeline
-$bourbon: ("rails-asset-pipeline": function-exists(font-url))
-

frontend/src/global_styles/content/_accounts.sass

@@ -96,8 +96,7 @@
     padding: 0.5rem 0.5rem 0.5rem 2rem
     margin-left: 10px
     margin-bottom: 10px
-    // Todo for task #33508
-    //background-image: image-url('auth_provider-developer.png')
+    background-image: url('~assets/images/auth_provider-developer.png')
     background-size: 20px 20px
     background-repeat: no-repeat
     background-position: 5px center

frontend/src/global_styles/openproject/_index.sass

@@ -8,7 +8,3 @@
 @import mixins
 @import onboarding
 @import scm
-
-// allow plugins to hook into global assets
-// Todo for task #33508
-// @import openproject/plugins