Remove no longer needed test code

Part of https://gitlab.com/gitlab-org/quality/quality-engineering/team-tasks/-/work_items/1825 refactor

app/assets/javascripts/projects/settings/components/default_branch_selector.vue

@@ -33,6 +33,5 @@ export default {
     :translations="$options.i18n"
     name="project[default_branch]"
     data-testid="default-branch-dropdown"
-    data-qa-selector="default_branch_dropdown"
   />
 </template>

app/views/projects/branch_defaults/_show.html.haml

@@ -14,4 +14,4 @@
       %input{ name: 'update_section', type: 'hidden', value: 'js-issue-settings' }
         = render 'projects/branch_defaults/default_branch_fields', f: f
         = render 'projects/branch_defaults/branch_names_fields', f: f
-      = f.submit _('Save changes'), pajamas_button: true, data: { qa_selector: 'save_changes_button' }
+      = f.submit _('Save changes'), pajamas_button: true

qa/qa/page/project/settings/default_branch.rb

-# frozen_string_literal: true
-
-module QA
-  module Page
-    module Project
-      module Settings
-        class DefaultBranch < Page::Base
-          include ::QA::Page::Component::Dropdown
-
-          view 'app/views/projects/branch_defaults/_show.html.haml' do
-            element :save_changes_button
-          end
-
-          view 'app/assets/javascripts/projects/settings/components/default_branch_selector.vue' do
-            element :default_branch_dropdown
-          end
-
-          def set_default_branch(branch)
-            expand_select_list
-            search_and_select(branch)
-          end
-
-          def click_save_changes_button
-            find('.btn-confirm').click
-          end
-        end
-      end
-    end
-  end
-end
-
-QA::Page::Project::Settings::DefaultBranch.prepend_mod_with('Page::Project::Settings::DefaultBranch', namespace: QA)

qa/qa/page/project/settings/repository.rb

@@ -64,14 +64,6 @@ def expand_protected_tags(&block)
           def expand_branch_rules
             expand_content('branch-rules-content')
           end
-
-          def expand_default_branch(&block)
-            within('#branch-defaults-settings') do
-              find('.btn-default').click do
-                DefaultBranch.perform(&block)
-              end
-            end
-          end
         end
       end
     end