Remove skip_web_ui_code_owner_validations feature flag

ee/lib/ee/gitlab/checks/diff_check.rb

@@ -20,22 +20,11 @@ module EE
         end
 
         def validate_code_owners?
-          return false if updated_from_web? && skip_web_ui_code_owner_validations?
+          return false if updated_from_web?
 
           project.branch_requires_code_owner_approval?(branch_name)
         end
 
-        # To allow self-hosted installations to ignore CODEOWNERS rules when
-        # clicking Merge in the UI. By default, these rules are not skipped.
-        #
-        # Issue to remove this feature flag:
-        # https://gitlab.com/gitlab-org/gitlab/-/issues/217427
-        def skip_web_ui_code_owner_validations?
-          return true unless ::Feature.enabled?(:use_legacy_codeowner_validations)
-
-          ::Feature.enabled?(:skip_web_ui_code_owner_validations, project)
-        end
-
         def validate_code_owners
           lambda do |paths|
             validator = ::Gitlab::CodeOwners::Validator.new(project, branch_name, paths)

ee/spec/lib/gitlab/checks/diff_check_spec.rb

@@ -125,52 +125,12 @@ RSpec.describe Gitlab::Checks::DiffCheck do
             expect(subject).to receive(:updated_from_web?).and_return(true)
           end
 
-          context "when use_legacy_codeowner_validations is enabled" do
-            before do
-              stub_feature_flags(use_legacy_codeowner_validations: true)
-            end
-
-            context "when skip_web_ui_code_owner_validations is disabled" do
-              before do
-                stub_feature_flags(skip_web_ui_code_owner_validations: false)
-                allow(project).to receive(:branch_requires_code_owner_approval?)
-                  .once.and_return(true)
-              end
-
-              it "returns an array of Proc(s)" do
-                validations = subject.send(:path_validations)
-
-                expect(validations.any?).to be_truthy
-                expect(validations.any? { |v| !v.is_a? Proc }).to be_falsy
-              end
-
-              context "when skip_web_ui_code_owner_validations is enabled" do
-                before do
-                  stub_feature_flags(skip_web_ui_code_owner_validations: true)
-                  expect(project).not_to receive(:branch_requires_code_owner_approval?)
-                end
-
-                it "returns an empty array" do
-                  expect(subject.send(:path_validations)).to eq([])
-                end
-              end
-            end
-          end
-
-          context "when use_legacy_codeowner_validations is disabled" do
-            before do
-              stub_feature_flags(use_legacy_codeowner_validations: false)
-
-              expect(project).not_to receive(:branch_requires_code_owner_approval?)
-            end
-
           it "returns an empty array" do
             expect(subject.send(:path_validations)).to eq([])
           end
         end
       end
     end
-    end
 
     context 'file name rules' do
       # Notice that the commit used creates a file named 'README'