Resolved uptime monitor issues don't trigger webhook alerts

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

1. Create an internal integration with a webhook at alerts for issues (created, resolved, assigned, archived, unresolved)
2. Create an uptime monitor for a website that will return healthy checks
3. Make a change to the website that will cause the uptime monitor to miss checks and create an uptime issue
4. Make a change tot he website so it returns healthy checks again, which makes Sentry mark the uptime issue as resolved

### Expected Result

We receive an alert via the webhook that the uptime issue was created and/or unresolved, and then receive another alert about the issue being resolved.

### Actual Result

We do not receive an webhook alert when the uptime issue is marked as unresolved. It looks like there's no API to mark this status.

Screenshots and links from my support test org:


Link to internal integration dashboard [here](https://dragonfruit-us.sentry.io/settings/developer-settings/webhook-for-uptime-checks-ee9dee/dashboard/)
Link to uptime issue [here](https://dragonfruit-us.sentry.io/issues/7258066924/?query=&referrer=issue-stream)

### Product Area

APIs

### Link

_No response_

### DSN

_No response_

### Version

_No response_

Start with the internal integration webhook event handling and the uptime monitor resolution flow described in the reproduction steps. Trace how created, unresolved, and resolved events are emitted, then verify through the listed SaaS steps that a resolved uptime issue produces the expected webhook alert.

Written by the indexing model from the issue text.