Merge branch 'rs-warm-capybara-only-in-ci' into 'master'

Don't attempt to warm the Capybara cache outside of CI

See merge request !12761

spec/support/test_env.rb

@@ -206,6 +206,7 @@ module TestEnv
   # Otherwise they'd be created by the first test, often timing out and
   # causing a transient test failure
   def eager_load_driver_server
+    return unless ENV['CI']
     return unless defined?(Capybara)
     puts "Starting the Capybara driver server..."