NoMethodError: undefined method `test_suites' for nil:NilClass

https://sentry.gitlab.net/gitlab/devgitlaborg/issues/754701/

NoMethodError: undefined method `test_suites' for nil:NilClass
  gitlab/ci/reports/test_reports_comparer.rb:18:in `block in suite_comparers'
    head_reports.test_suites.map do |name, test_suite|
  gitlab/utils/strong_memoize.rb:30:in `strong_memoize'
    instance_variable_set(ivar(name), yield)
  gitlab/ci/reports/test_reports_comparer.rb:17:in `suite_comparers'
    strong_memoize(:suite_comparers) do
  gitlab/ci/reports/test_reports_comparer.rb:25:in `total_status'
    if suite_comparers.any? { |suite| suite.total_status == TestCase::STATUS_FAILED }
  grape_entity/delegator/plain_object.rb:8:in `delegate'
    object.send attribute
...
(86 additional frame(s) were not displayed)

undefined method `test_suites' for nil:NilClass