Remove a comment on how to reproduce AVM issue 717

The comment is no longer necessary because I converted the failing
libavif test to to AVM unit tests in
https://gitlab.com/AOMediaCodec/avm/-/merge_requests/1902.

tests/gtest/avifavmtest.cc

diff --git a/tests/gtest/avifavmtest.cc b/tests/gtest/avifavmtest.cc
index ff084b4..3ed4449 100644
--- a/tests/gtest/avifavmtest.cc
+++ b/tests/gtest/avifavmtest.cc
@@ -75,10 +75,6 @@
                                  Values(AVIF_PIXEL_FORMAT_YUV444),
                                  /*alpha=*/Values(false)));
 
-// The width in this test was originally 2 and that detected
-// https://gitlab.com/AOMediaCodec/avm/-/issues/717. 5 is the smallest width
-// that allows this test to pass. To reproduce the bug, decrease width to 4, 3,
-// or 2.
 INSTANTIATE_TEST_SUITE_P(HighBitDepthAndEvenDimensions, AvmTest,
                          Combine(/*width=*/Values(5), /*height=*/Values(34),
                                  /*depth=*/Values(10, 12),