API improvements for serverName in barman configuration #334
Description
The API documentation for serverName in the barman configuration is generated from the barman-cloud module and is also included in the in-tree implementation in CNPG. However, we should guide the users and prevent them from setting the serverName when it is ignored.
We should include the notice in the global documentation of the ObjectStore type, together with a CEL rule to prevent the value from being set.
Originally posted by @mnencia in #330 (comment)