Include `laziness` in `GraphqlHelpers`

A number of GraphQL tests include both `GraphqlHelpers` and
`Gitlab::Graphql::Laziness`. This change has `GraphqlHelpers` include
`Gitlab::Graphql::Laziness` so it's available to tests.

ee/spec/graphql/resolvers/epic_issues_resolver_spec.rb

@@ -3,7 +3,6 @@
 require 'spec_helper'
 
 RSpec.describe Resolvers::EpicIssuesResolver do
-  include ::Gitlab::Graphql::Laziness
   include GraphqlHelpers
 
   let_it_be(:current_user) { create(:user) }

ee/spec/graphql/resolvers/vulnerabilities_grade_resolver_spec.rb

@@ -4,7 +4,6 @@ require 'spec_helper'
 
 RSpec.describe Resolvers::VulnerabilitiesGradeResolver do
   include GraphqlHelpers
-  include ::Gitlab::Graphql::Laziness
 
   subject do
     force(resolve(described_class, obj: group, args: args, ctx: { current_user: user }))

spec/graphql/resolvers/concerns/caching_array_resolver_spec.rb

@@ -4,7 +4,6 @@ require 'spec_helper'
 
 RSpec.describe ::CachingArrayResolver do
   include GraphqlHelpers
-  include Gitlab::Graphql::Laziness
 
   let_it_be(:admins) { create_list(:user, 4, admin: true) }
   let(:query_context) { { current_user: admins.first } }

spec/graphql/resolvers/package_details_resolver_spec.rb

@@ -4,7 +4,6 @@ require 'spec_helper'
 
 RSpec.describe Resolvers::PackageDetailsResolver do
   include GraphqlHelpers
-  include ::Gitlab::Graphql::Laziness
 
   let_it_be_with_reload(:project) { create(:project) }
   let_it_be(:user) { project.owner }

spec/support/helpers/graphql_helpers.rb

 # frozen_string_literal: true
 
 module GraphqlHelpers
+  def self.included(base)
+    base.include(::Gitlab::Graphql::Laziness)
+  end
+
   MutationDefinition = Struct.new(:query, :variables)
 
   NoData = Class.new(StandardError)