Deprecate client.type (#104574)

client.type existed from the days of the node client existing alongside
the java client. Since the node client no longer exists, it no longer
serves a purpose, and is already ignored. Yet the setting still exists.
This commit deprecates the client.type node setting.

docs/changelog/104574.yaml

@@ -0,0 +1,10 @@
+pr: 104574
+summary: Deprecate `client.type`
+area: Infra/Core
+type: deprecation
+issues: []
+deprecation:
+  title: Deprecate `client.type`
+  area: Cluster and node setting
+  details: The node setting `client.type` has been ignored since the node client was removed in 8.0. The setting is now deprecated and will be removed in a future release.
+  impact: Remove the `client.type` setting from `elasticsearch.yml`

server/src/main/java/org/elasticsearch/client/internal/Client.java

@@ -78,7 +78,7 @@ public interface Client extends ElasticsearchClient {
             case "node", "transport" -> s;
             default -> throw new IllegalArgumentException("Can't parse [client.type] must be one of [node, transport]");
         };
-    }, Property.NodeScope);
+    }, Property.NodeScope, Property.Deprecated);
 
     /**
      * The admin client that can be used to perform administrative operations.