Can't Delete Downtime Issues

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

1. Be Owner of org
2. Try to delete a Downtime issue created by an uptime monitor
3. See that delete button is greyed out

Deleting the issue through the api works: https://docs.sentry.io/api/events/remove-an-issue/

### Expected Result

To be able to click the delete button

### Actual Result

Can not click delete button.

### Product Area

Issues

### Link

_No response_

### DSN

_No response_

### Version

_No response_

Start by reproducing the SaaS issue as an organization owner and tracing the Issues delete control for downtime issues created by an uptime monitor. Confirm that the UI enables deletion consistently with the documented API behavior, and verify the resulting behavior with a regression check.

Written by the indexing model from the issue text.