If a spec such as `wiki_pipeline_spec.rb` included a NULL byte in the
example text, then the `insert-rspec-profiling-data` script would fail
with an `invalid byte sequence` error
(e.g. https://gitlab.com/gitlab-org/gitlab/-/jobs/386527522).

To avoid this, we do two things:

1. Drop the NULL byte from the example test.
2. Modify the `insert-rspec-profiling-data` script to sanitize the CSV.

Closes https://gitlab.com/gitlab-org/gitlab/issues/120012