Allow configuring defaults for celery-beat

### Problem Statement Basically, I have the same request as [posted before](https://github.com/getsentry/sentry/issues/64881), I'd like to be able to configure these defaults for globally/per project. As @gaprl writes in that post, many SDKs support these configuration options, which would be ok as well - but that doesn't seem to be the case for automatically-discovered celery-beat tasks, which is what I'm setting up at the moment. There's no mention in [the docs](https://docs.sentry.io/platforms/python/integrations/celery/crons/#celery-beat-auto-discovery). However, we can [configure that for manual monitors](https://docs.sentry.io/platforms/python/crons/#configuring-cron-monitors) and I tried adding `@monitor(monitor_config={...})` to auto-discovered tasks, but that didn't work. Do I overlook something or is it indeed not possible to configure these values for auto-discovered beat tasks? ### Solution Brainstorm Ideally we'd be able to configure global/project defaults. Failing that, configuring that via decorator in code would still be much preferable to manually configure each monitor via the Sentry web UI. ### Product Area Crons