Remove add_member Flow method

It duplicates Resource::Project.add_member

qa/qa/flow/project.rb

@@ -5,16 +5,6 @@ module QA
     module Project
       module_function
 
-      def add_member(project:, username:)
-        project.visit!
-
-        Page::Project::Menu.perform(&:click_members)
-
-        Page::Project::Members.perform do |member_settings|
-          member_settings.add_member(username)
-        end
-      end
-
       def go_to_create_project_from_template
         if Page::Project::NewExperiment.perform(&:shown?)
           Page::Project::NewExperiment.perform(&:click_create_from_template_link)

qa/qa/specs/features/browser_ui/2_plan/email/trigger_email_notification_spec.rb

@@ -20,7 +20,12 @@ module QA
       end
 
       it 'is received by a user for project invitation', testcase: 'https://gitlab.com/gitlab-org/quality/testcases/-/issues/676' do
-        Flow::Project.add_member(project: project, username: user.username)
+        project.visit!
+
+        Page::Project::Menu.perform(&:click_members)
+        Page::Project::Members.perform do |member_settings|
+          member_settings.add_member(user.username)
+        end
 
         expect(page).to have_content(/@#{user.username}(\n| )?Given access/)
 

qa/qa/specs/features/browser_ui/2_plan/issue/check_mentions_for_xss_spec.rb

@@ -20,7 +20,7 @@ module QA
       before do
         Flow::Login.sign_in
 
-        Flow::Project.add_member(project: project, username: user.username)
+        project.add_member(user)
 
         Resource::Issue.fabricate_via_api! do |issue|
           issue.project = project