Selective Hazelcast support

Hello.

Enhancement
To my understanding of the docs at https://docs.spring-boot-admin.com/3.5.5/docs/server/server#clustering and from trials I did in the past, to have Hazelcast clustering support in an SBA server, both the notification and event maps need to be configured, because otherwise it would crash (e.g.: https://github.com/codecentric/spring-boot-admin/issues/4258).
Given the weird behavior in https://github.com/codecentric/spring-boot-admin/issues/4599, which is not fixable if not by destroying the environment completely (on rolling updates / zero-downtime deployments, the event cache gets migrated from one old node to new one which is starting automatically), I would like to have the possibility to have only the notifications clustered - in order to avoid duplicates - and not the events as well.
Of course, to make the feature generic enough and profitable also by others, ideally it should be possible to say for each of the caches if they should be created or not.

Start with the server clustering documentation and the behavior described in issues #4258 and #4599. Determine how notification and event caches are configured, then make cache creation independently selectable so notifications can be clustered without events; done means the requested selective configuration works without the reported crashes or duplicate notifications.