[babel] Remove unsafe calls to path.stop()

Discovered this in a recent attempt at syncing Forget to Meta, it seems that calling path.stop() is unsafe as it appears to have strange behavior in plugins that come after. This resulted in `import type {...}` not being compiled away in the post-babel output which isn't valid JS syntax. Removing the `stop()` calls fixes it Test plan: made these changes locally, synced my local changes to Meta and reran - in simulator and observe that it now runs and doesn't throw a syntax error