Merge branch 'logged-out-marketing-header/experiment-class' into 'master'

Define class for logged_out_marketing_header experiment

See merge request gitlab-org/gitlab!83714

app/experiments/logged_out_marketing_header_experiment.rb

+# frozen_string_literal: true
+
+class LoggedOutMarketingHeaderExperiment < ApplicationExperiment
+  # These default behaviors are overriden in ApplicationHelper and header
+  # template partial
+  control {}
+  candidate {}
+  variant(:trial_focused) {}
+end