LUCENE-10040: Update HnswGraph javadoc related to deletions

Previously it claimed the search method did not handle deletions.

Author: jtibshirani

lucene/core/src/java/org/apache/lucene/util/hnsw/HnswGraph.java

@@ -50,8 +50,8 @@
  * </ul>
  *
  * <p>Note: The graph may be searched by multiple threads concurrently, but updates are not
- * thread-safe. Also note: there is no notion of deletions. Document searching built on top of this
- * must do its own deletion-filtering.
+ * thread-safe. The search method optionally takes a set of "accepted nodes", which can be used to
+ * exclude deleted documents.
  */
 public final class HnswGraph extends KnnGraphValues {