Remove deprecated icon helper in favor of sprite_icon

app/helpers/icons_helper.rb

@@ -8,22 +8,6 @@ module IconsHelper
 
   DEFAULT_ICON_SIZE = 16
 
-  # Creates an icon tag given icon name(s) and possible icon modifiers.
-  #
-  # Right now this method simply delegates directly to `fa_icon` from the
-  # font-awesome-rails gem, but should we ever use a different icon pack in the
-  # future we won't have to change hundreds of method calls.
-  # @deprecated use sprite_icon to render a SVG icon
-  def icon(names, options = {})
-    if (options.keys & %w[aria-hidden aria-label data-hidden]).empty?
-      # Add 'aria-hidden' and 'data-hidden' if they are not set in options.
-      options['aria-hidden'] = true
-      options['data-hidden'] = true
-    end
-
-    options.include?(:base) ? fa_stacked_icon(names, options) : fa_icon(names, options)
-  end
-
   def custom_icon(icon_name, size: DEFAULT_ICON_SIZE)
     memoized_icon("#{icon_name}_#{size}") do
       # We can't simply do the below, because there are some .erb SVGs.

doc/development/fe_guide/icons.md

@@ -48,8 +48,6 @@ sprite_icon(icon_name, size: nil, css_class: '')
 </svg>
 ```
 
-**Please note:** The `icon(icon_name, options: {})` helper function is deprecated and should not be used anymore.
-
 ### Usage in Vue
 
 [GitLab UI](https://gitlab-org.gitlab.io/gitlab-ui/), our components library, provides a component to display sprite icons.

spec/helpers/icons_helper_spec.rb

@@ -5,21 +5,6 @@ require 'spec_helper'
 RSpec.describe IconsHelper do
   let(:icons_path) { ActionController::Base.helpers.image_path("icons.svg") }
 
-  describe 'icon' do
-    it 'returns aria-hidden by default' do
-      star = icon('star')
-
-      expect(star['aria-hidden']).to eq 'aria-hidden'
-    end
-
-    it 'does not return aria-hidden if aria-label is set' do
-      up = icon('up', 'aria-label' => 'up')
-
-      expect(up['aria-hidden']).to be_nil
-      expect(up['aria-label']).to eq 'aria-label'
-    end
-  end
-
   describe 'sprite_icon_path' do
     it 'returns relative path' do
       expect(sprite_icon_path).to eq(icons_path)