Update server-side-apply.md

Deleted the duplicate section of the issue(Server-Side Apply for custom resources ) kubernetes#43806

content/en/docs/reference/using-api/server-side-apply.md

@@ -214,17 +214,6 @@ Here's an example of a Server-Side Apply message body (fully specified intent):
 of a **patch** request to a valid `v1/configmaps` resource, and with the
 appropriate request `Content-Type`).
 
-## Server-Side Apply for custom resources {#custom-resources}
-
-By default, Server-Side Apply treats
-{{< glossary_tooltip term_id="CustomResourceDefinition" text="custom resources" >}}
-as unstructured data. All keys are treated the same as if they were struct fields for
-a built-in API, and all lists are considered atomic.
-
-If the CustomResourceDefinition defines a
-[schema](/docs/reference/kubernetes-api/extend-resources/custom-resource-definition-v1/#JSONSchemaProps)
-that contains annotations as defined in [Merge strategy](#merge-strategy),
-then these annotations will be used when merging objects of this type.
 
 ## Operations in scope for field management {#apply-and-update}