[real-time] Message for existing items is not updated when it changes

### Environment

SaaS (https://sentry.io/)

### Version

_No response_

### Link

_No response_

### DSN

_No response_

### Steps to Reproduce

1. Log a message "Test warning 1".
2. Log a message "Test warning 2", from the same place.

### Expected Result

When real-time updates are enabled, the message should be updated and display "Test warning 2".

### Actual Result

The message remains as "Test warning 1", even though the event count and last seen times are updated.