OpenTimeilineIO is mature

OpenTimelineIO Is mature and in wide deployment, foundationally to certain applications to the degree that it is a load bearing member. Naming it Beta after a decade of rigorous and active development does it a disservice and undercuts the achievement of the library.

The issue names no file, test, or entry point. First locate where OpenTimelineIO is labeled Beta in the project documentation or release metadata, then confirm the intended wording with maintainers; done means the outdated designation is updated consistently.

Written by the indexing model from the issue text.