Fix typing of BulkUpdateOperation.RetryOnConflict (#7841)

Author: flobernd

src/Elastic.Clients.Elasticsearch/Types/Core/Bulk/BulkUpdateOperation.cs

@@ -19,7 +19,7 @@ protected internal BulkUpdateOperation() : base() { }
 	private static byte _newline => (byte)'\n';
 
 	[JsonPropertyName("retry_on_conflict")]
-	public bool? RetryOnConflict { get; set; }
+	public int? RetryOnConflict { get; set; }
 
 	protected override string Operation => "update";