Lower PSNR thresholds after commit b4f03d7

Fix AV1/SharpnessAllIntraTestLarge.SharpnessPSNRTest/4 and
AV1/SharpnessAllIntraTestLarge.SharpnessPSNRTest/5 failures.

Bug: aomedia:375221136
Change-Id: Ie5afb81d843bc82800f5bf9d84a45dd3564a5591

test/sharpness_test.cc

diff --git a/test/sharpness_test.cc b/test/sharpness_test.cc
index d3815fd..53fe137 100644
--- a/test/sharpness_test.cc
+++ b/test/sharpness_test.cc
@@ -34,7 +34,7 @@
                        { static_cast<int>(::libaom_test::kAllIntra),
                          { { 3, { { 2, 42.2 }, { 5, 42.2 } } },
                            { 6, { { 2, 41.8 }, { 4, 41.9 }, { 5, 41.9 } } },
-                           { 9, { { 2, 41.0 }, { 5, 41.0 } } } } } };
+                           { 9, { { 2, 40.9 }, { 5, 40.9 } } } } } };
 
 // This class is used to test sharpness parameter configured through control
 // call using AOME_SET_SHARPNESS for different encoder configurations.