Merge branch '273559-consider-running-crystalball-only-on-2-hourly-pipeline' into 'master'

Enable crystalball only on 2-hourly pipeline

See merge request gitlab-org/gitlab!46418

spec/crystalball_env.rb

@@ -6,7 +6,7 @@ module CrystalballEnv
   extend self
 
   def start!
-    return unless ENV['CRYSTALBALL'] && ENV['CI_PIPELINE_SOURCE'] == 'schedule'
+    return unless ENV['CRYSTALBALL'] && ENV['CI_PIPELINE_SOURCE'] == 'schedule' && ENV['FREQUENCY'] == '2-hourly'
 
     require 'crystalball'
     require_relative '../tooling/lib/tooling/crystalball/coverage_lines_execution_detector'