Remove :generic_canonical feature flag

app/helpers/page_layout_helper.rb

@@ -164,7 +164,6 @@ module PageLayoutHelper
     strong_memoize(:generic_canonical_url) do
       next unless request.get? || request.head?
       next unless generate_generic_canonical_url?
-      next unless Feature.enabled?(:generic_canonical, current_user)
 
       # Request#url builds the url without the trailing slash
       request.url

config/feature_flags/development/generic_canonical.yml

----
-name: generic_canonical
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/46435
-rollout_issue_url:
-type: development
-group: group::editor
-default_enabled: false

spec/features/canonical_link_spec.rb

@@ -67,18 +67,4 @@ RSpec.describe 'Canonical link' do
     let(:request_url) { explore_root_path }
     let(:expected_url) { explore_projects_url }
   end
-
-  context 'when feature flag generic_canonical is disabled' do
-    before do
-      stub_feature_flags(generic_canonical: false)
-    end
-
-    it_behaves_like 'does not show canonical link' do
-      let(:request_url) { issue_request + '/' }
-    end
-
-    it_behaves_like 'does not show canonical link' do
-      let(:request_url) { project_request + '/' }
-    end
-  end
 end

spec/helpers/page_layout_helper_spec.rb

@@ -196,16 +196,6 @@ RSpec.describe PageLayoutHelper do
       it_behaves_like 'does not return a canonical url' do
         let(:method) { 'PUT' }
       end
-
-      context 'when feature flag generic_canonical is disabled' do
-        let(:method) { 'GET' }
-
-        before do
-          stub_feature_flags(generic_canonical: false)
-        end
-
-        it_behaves_like 'does not return a canonical url'
-      end
     end
   end