proto: Add `ZedProTrial` to `Plan` (#28885)

This PR adds the `ZedProTrial` member to the `Plan` enum.

Release Notes:

- N/A
97b044acf5Marshall Bowers committed on 4/16/2025, 6:13:00 PM· committed by GitHubparent1e25e6b
6 files changedLine totals unavailable