Remove latest_builds_report_results preloading in pipeline serializer

The preloading was introduced in https://gitlab.com/gitlab-org/gitlab/-/merge_requests/37582.
This preloading creates some mega queries in mega projects having
complicated build pipelines. Plus, latest_builds_report_results are not
a part of the serialization anymore.

app/serializers/pipeline_serializer.rb

@@ -42,7 +42,6 @@ class PipelineSerializer < BaseSerializer
     [
       :cancelable_statuses,
       :latest_statuses_ordered_by_stage,
-      :latest_builds_report_results,
       :retryable_builds,
       :stages,
       :latest_statuses,