Java client Issues batch 6 partial backport (#2598)

Author: l-trotta

output/openapi/elasticsearch-serverless-openapi.json

@@ -36,7 +36,7 @@ export class Operation {
   /**
    * The ID of the document.
    */
-  _id: Id
+  _id?: Id
   /**
    * The index of the document.
    */

output/schema/schema.json

@@ -73,7 +73,7 @@ export class NodeInfoSettings {
   repositories?: NodeInfoRepositories
   discovery?: NodeInfoDiscover
   action?: NodeInfoAction
-  client: NodeInfoClient
+  client?: NodeInfoClient
   http: NodeInfoSettingsHttp
   bootstrap?: NodeInfoBootstrap
   transport: NodeInfoSettingsTransport
@@ -218,7 +218,7 @@ export class NodeInfoSettingsTransportFeatures {
 }
 
 export class NodeInfoSettingsNetwork {
-  host: Host
+  host?: Host
 }
 
 export class NodeInfoIngest {
@@ -280,7 +280,7 @@ export class NodeInfoXpackLicenseType {
 
 export class NodeInfoScript {
   allowed_types: string
-  disable_max_compilations_rate: string
+  disable_max_compilations_rate?: string
 }
 
 export class NodeInfoSearch {