Add deprecated message

Author: MBkkt

ydb/core/protos/index_builder.proto

@@ -109,7 +109,7 @@ message TEvListResponse {
 
 enum EBuildStatus {
     INVALID = 0;
-    ACCEPTED = 1;
+    ACCEPTED = 1; // DEPRECATED don't use it, it does nothing, we cannot remove it for now, because old nodes can send it
     IN_PROGRESS = 2;
     DONE = 3;