Remove outdated sub-packages documentation from package-info

Remove the sub-packages list from aggregation package-info.java as it was
already outdated (missing the support package) and violates separation of
concerns - outer packages should not document implementation details of
inner packages.

This avoids maintenance burden when sub-packages are added or modified.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: yiyuabc

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/aggregation/package-info.java

@@ -11,10 +11,5 @@
  *
  * <p>This package uses the converter/registry pattern via {@link org.opensearch.transport.grpc.spi.AggregationBuilderProtoConverterRegistry}
  * to route aggregation containers to their type-specific converters with plugin extensibility support.
- *
- * <p>Sub-packages:
- * <ul>
- *   <li>{@code metrics} - Metric aggregations (Min, Max, etc.)</li>
- * </ul>
  */
 package org.opensearch.transport.grpc.proto.request.search.aggregation;