Implement wiki page async load

In this commit we're removing the ff `wiki_async_load` to
globally enable the feature to load every wiki page async.

Changelog: added

app/controllers/concerns/wiki_actions.rb

@@ -308,8 +308,7 @@ module WikiActions
   end
 
   def load_content?
-    return false if %w[history destroy diff].include?(params[:action])
-    return false if params[:action] == 'show' && Feature.enabled?(:wiki_async_load, container, default_enabled: :yaml)
+    return false if %w[history destroy diff show].include?(params[:action])
 
     true
   end

app/views/shared/wikis/show.html.haml

@@ -27,9 +27,6 @@
       - if can?(current_user, :create_wiki, @wiki.container) && @page.latest? && @valid_encoding
         = link_to sprite_icon('pencil', css_class: 'gl-icon'), wiki_page_path(@wiki, @page, action: :edit), title: 'Edit', role: "button", class: 'btn gl-button btn-icon btn-default js-wiki-edit', data: { qa_selector: 'edit_page_button', testid: 'wiki_edit_button' }
 
-  - if Feature.enabled?(:wiki_async_load, @wiki.container, default_enabled: :yaml)
   .js-async-wiki-page-content.md.gl-pt-2{ data: { qa_selector: 'wiki_page_content', testid: 'wiki_page_content', tracking_context: wiki_page_tracking_context(@page).to_json, get_wiki_content_url: wiki_page_render_api_endpoint(@page) } }
-  - else
-    = render 'shared/wikis/wiki_content'
 
 = render 'shared/wikis/sidebar'

config/feature_flags/development/wiki_async_load.yml

----
-name: wiki_async_load
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/82394
-rollout_issue_url:
-milestone: '14.9'
-type: development
-group: group::editor
-default_enabled: false

ee/spec/features/groups/wikis_spec.rb

@@ -14,7 +14,6 @@ RSpec.describe 'Group wikis', :js do
     wiki.container.add_owner(user)
   end
 
-  shared_examples 'wiki feature tests' do
   it_behaves_like 'User creates wiki page'
   it_behaves_like 'User deletes wiki page'
   it_behaves_like 'User previews wiki changes'
@@ -25,15 +24,4 @@ RSpec.describe 'Group wikis', :js do
   it_behaves_like 'User views wiki pages'
   it_behaves_like 'User views wiki sidebar'
   it_behaves_like 'User views Git access wiki page'
-  end
-
-  it_behaves_like 'wiki feature tests'
-
-  context 'when feature flag :wiki_async_load is disabled' do
-    before do
-      stub_feature_flags(wiki_async_load: false)
-    end
-
-    it_behaves_like 'wiki feature tests'
-  end
 end

spec/features/projects/wikis_spec.rb

@@ -8,7 +8,6 @@ RSpec.describe 'Project wikis', :js do
   let(:wiki) { create(:project_wiki, user: user, project: project) }
   let(:project) { create(:project, namespace: user.namespace, creator: user) }
 
-  shared_examples 'wiki feature tests' do
   it_behaves_like 'User creates wiki page'
   it_behaves_like 'User deletes wiki page'
   it_behaves_like 'User previews wiki changes'
@@ -19,15 +18,4 @@ RSpec.describe 'Project wikis', :js do
   it_behaves_like 'User views wiki pages'
   it_behaves_like 'User views wiki sidebar'
   it_behaves_like 'User views Git access wiki page'
-  end
-
-  it_behaves_like 'wiki feature tests'
-
-  context 'when feature flag :wiki_async_load is disabled' do
-    before do
-      stub_feature_flags(wiki_async_load: false)
-    end
-
-    it_behaves_like 'wiki feature tests'
-  end
 end