Enable test IoStatsTest.AnimationObuSize (#3031)

The libaom version should be recent enough.

tests/gtest/avifiostatstest.cc

diff --git a/tests/gtest/avifiostatstest.cc b/tests/gtest/avifiostatstest.cc
index 992ab81..b889e33 100644
--- a/tests/gtest/avifiostatstest.cc
+++ b/tests/gtest/avifiostatstest.cc
@@ -97,9 +97,7 @@
   EXPECT_GT(io_stats.alphaOBUSize, 0u);
 }
 
-// Disabled because segfault happens with some libaom versions (such as 3.5.0)
-// but not others (such as 3.6.0). TODO(yguyon): Find the commit that fixed it.
-TEST(DISABLED_IoStatsTest, AnimationObuSize) {
+TEST(IoStatsTest, AnimationObuSize) {
   avifIOStats io_stats;
   ASSERT_TRUE(GetIoStatsFromEncode(io_stats, AVIF_QUALITY_LOSSLESS,
                                    AVIF_QUALITY_LOSSLESS,