Specific environments not selectable when editing monitor

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

**Description**
When editing a crons monitor, it seems that you can only select "All Environments":

Support case with customer org & example: https://sentry.zendesk.com/agent/tickets/107595

Steps:
1. Create a monitor
2. After creation -> edit monitor
3. Try selecting specific environment

### Expected Result

Select specific environment when editing monitor

### Actual Result

Only able to select all environments

### Product Area

Crons

### Link

_No response_

### DSN

_No response_

### Version

_No response_

┆Issue is synchronized with this [Jira Improvement](https://getsentry.atlassian.net/browse/FEEDBACK-2098) by [Unito](https://www.unito.io)