Remove manual Companion and cronbot jobs to sync stratum and sv2-apps

[bit-aloo]

This might be something worth looking into:

https://blog.rust-lang.org/inside-rust/2026/06/04/how-josh-helps-rust-manage-code-across-multiple-repositories/

The Rust project maintains several repositories, such as miri, RA, cargo, and clippy. Josh is used to synchronize changes across these repositories. When a change in the Rust repository requires corresponding updates in one of these projects, Josh can automatically propagate those changes and keep the related PRs in sync.

This feels quite similar to our usecase on how we handle changes in the stratum repo that need to be reflected in sv2-apps. We already have the companion setup, and the cron bot automatically opens PRs in sv2-apps to update lock files whenever a PR is merged into Stratum.

It might be worth exploring whether Josh could simplify or replace parts of our current workflow.

[plebhash]

https://josh-project.dev/docs/