Drop support for `data-track-event`
After working on #332650 (closed) we can safely remove support for data-track-event.
Reference in the docs: https://docs.gitlab.com/ee/development/snowplow/index.html#tracking-with-data-attributes
After working on #332650 (closed) we can safely remove support for data-track-event.
Reference in the docs: https://docs.gitlab.com/ee/development/snowplow/index.html#tracking-with-data-attributes