feat(deno): Support Deno.CronSchedule for cron jobs (#9880)

This PR adds support for `Deno.CronSchedule`. Since the `CronSchedule`
type cannot be fully expressed by the Sentry `IntervalSchedule`, I
instead copied the Deno code to convert to `CrontabSchedule`.

I also added `checkinMargin: 1` since the Deno docs state that on Deno
Deploy, crons can be up to 1 minute late.

Author: timfish