Remove code creating job hash from legacy CI config

lib/ci/gitlab_ci_yaml_processor.rb

@@ -68,8 +68,9 @@ module Ci
       @jobs = {}
-      @config.except!(*ALLOWED_YAML_KEYS)
-      @config.each { |name, param| add_job(name, param) }
+      @ci_config.jobs.each do |name, param|
+        add_job(name, param)
+      end
       raise ValidationError, "Please define at least one job" if @jobs.none?
     end

lib/gitlab/ci/config.rb

@@ -8,7 +8,7 @@ module Gitlab
       # Temporary delegations that should be removed after refactoring
       #
       delegate :before_script, :image, :services, :after_script, :variables,
-               :stages, :cache, to: :@global
+               :stages, :cache, :jobs, to: :@global
       def initialize(config)
         @config = Loader.new(config).load!