Not possible to save Linear settings in alert

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

1. Create an alert in an org that has Linear integration
2. click on "Settings" at the _Then step, create a Linear issue with these Settings_ part
3. Modify the Linear settings
4. Hit Save
5. Open the settings again and the previously added settings are blank again

### Expected Result

The settings should be saved

### Actual Result

The settings are not saved

https://github.com/getsentry/sentry/assets/25980868/1096592d-511d-47fd-8b6a-a3d61401fee2

### Product Area

Settings - Integrations

### Link

_No response_

### DSN

_No response_

### Version

_No response_