Remove trailing whitespace in docs

doc/administration/docs_self_host.md

doc/administration/gitaly/praefect.md

doc/api/oauth2.md

doc/development/documentation/testing.md

doc/development/ee_features.md

doc/development/event_store.md

doc/development/experiment_guide/gitlab_experiment.md

doc/development/fe_guide/style/javascript.md

doc/development/import_project.md

...nt/merge_request_application_and_rate_limit_guidelines.md

doc/development/redis/new_redis_instance.md

doc/development/service_ping/index.md

doc/development/sidekiq/worker_attributes.md

doc/development/testing_guide/end_to_end/feature_flags.md

...elopment/testing_guide/end_to_end/rspec_metadata_tests.md

doc/integration/gitlab.md

doc/raketasks/backup_restore.md

doc/security/rate_limits.md

doc/subscriptions/index.md

doc/topics/autodevops/customize.md