dillon1000/react

Remove Passive flag from "before mutation" phase (#20038)

We don't need to visit passive effect nodes during before mutation.

The only reason we were previously was to schedule the root-level
passive effect callback as early as possible, but now that
`subtreeFlags` exists, we can check that instead.

This should reduce the amount of traversal during the commit phase,
particularly when mounting or updating large trees that contain many
passive effects.