fix: remove unnecessary console in `isDynamicPostpone` (#69457)
### What?
Remove `console.log(err)` in `isDynamicPostpone`, I think this should be
a debug console that was accidentally left behind.
### Why?
This will cause meaningless logs to appear in the console when we use
the `unstable_rethrow` API.
Co-authored-by: JJ Kasper <jj@jjsweb.site>
