Merge branch 'telemetry-70-remove-pendo-poc-from-staging' into 'master'

Backport: Removed pendo poc code

See merge request gitlab-org/gitlab-ce!31307

app/views/layouts/_head.html.haml

@@ -78,4 +78,3 @@
   = render 'layouts/google_analytics' if extra_config.has_key?('google_analytics_id')
   = render 'layouts/piwik' if extra_config.has_key?('piwik_url') && extra_config.has_key?('piwik_site_id')
   = render_if_exists 'layouts/snowplow'
-  = render_if_exists 'layouts/pendo' if Feature.enabled?(:pendo_tracking) && !Rails.env.test?