riegeli_dataset_io_test.diff

diff --git a/envlogger/backends/cc/riegeli_dataset_io_test.cc b/envlogger/backends/cc/riegeli_dataset_io_test.cc
index 28a0af5..62aa282 100644
--- a/envlogger/backends/cc/riegeli_dataset_io_test.cc
+++ b/envlogger/backends/cc/riegeli_dataset_io_test.cc
@@ -75,6 +75,7 @@ TEST(RiegeliDatasetTest, MetadataTest) {
   const auto actual_metadata = reader.Metadata();
   EXPECT_THAT(actual_metadata, Not(Eq(std::nullopt)));
   EXPECT_THAT(*actual_metadata, EqualsProto(metadata));
+  reader.Close();
 
   ENVLOGGER_EXPECT_OK(file::RecursivelyDelete(data_dir));
 }