Add a Service with a CLUSTER as its target breaks CONFIG SYNC

Tested on Maxscale 25.01.2

Create and test a dual Maxscale using configuration sync. Test the configuration sync is working by adding a new listener and verifying that it appears on the other Maxscale.

From the Admin GUI, Create new Service

• Router = readwritesplit
• Routing Targets
• Select Routing Targets = cluster
• Specify a cluster = monitor-01

The maxscale where the actions are in the admin GUI adds the new service successfully.

The maxscale that is to receive and apply the config gets an error:

2025-04-04 12:50:28   error  : (ConfigManager); Service 'rw-split-test' cannot use cluster 'monitor-01': Service uses targets

2025-04-04 12:50:28   error  : (ConfigManager); Could not find the service that 'monitor-01' relates to

2025-04-04 12:50:28   error  : (ConfigManager); Failed to sync configuration: Failed to update monitor 'monitor-01'