[UnitTest] Updated tolerances to avoid flaky unit test.

The result was correct, but the atol was just small enough to trigger
a CI error for a value that was close to zero in an unrelated PR at
#8670.

https://ci.tlcpack.ai/blue/organizations/jenkins/tvm/detail/PR-8670/16/pipeline/#step-236-log-1703

tests/python/relay/test_auto_scheduler_layout_rewrite_networks.py

@@ -179,7 +179,7 @@ def get_output(data, lib):
         actual_output = get_output(data, lib)
         expected_output = get_output(data, lib2)
 
-        tvm.testing.assert_allclose(actual_output, expected_output, rtol=1e-4, atol=1e-4)
+        tvm.testing.assert_allclose(actual_output, expected_output, rtol=1e-4, atol=2e-4)
 
 
 def test_conv2d():