Use explicit modes in avifyuv test CMake targets

tests/CMakeLists.txt

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index a48a5fd..e877590 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -42,7 +42,7 @@
     set_target_properties(avifyuv PROPERTIES LINKER_LANGUAGE "CXX")
 endif()
 target_link_libraries(avifyuv avif ${AVIF_PLATFORM_LIBRARIES})
-foreach(AVIFYUV_MODE 0 2) # Modes 1 and 3 take more than 2 minutes each so they are disabled.
+foreach(AVIFYUV_MODE limited rgb) # Modes drift and premultiply take more than 2 minutes each so they are disabled.
     add_test(NAME avifyuv_${AVIFYUV_MODE} COMMAND avifyuv -m ${AVIFYUV_MODE})
 endforeach()