update-tests-metadata aborting

Now that we added back rspec-profiling, we see that one of the test steps is generating NULL bytes. From https://gitlab.com/gitlab-org/gitlab/-/jobs/386527522:

687 	from /usr/local/bundle/gems/pg-1.1.4/lib/pg/connection.rb:173:in `copy_data'
688 	from /usr/local/bundle/gems/postgres-copy-1.4.1/lib/postgres-copy/acts_as_copy_target.rb:103:in `copy_from'
689 	from scripts/insert-rspec-profiling-data:38:in `block in insert_data'
690 	from scripts/insert-rspec-profiling-data:36:in `each'
691 	from scripts/insert-rspec-profiling-data:36:in `insert_data'
692 	from scripts/insert-rspec-profiling-data:43:in `<main>'

I'd really like to know which job is generating this:

750 2019-12-21 15:21:53 +0000 Inserting rspec_profiling/1576938614-209371fb171336e4-rspec-data.csv...