Add comment about avif_enable_warnings

Author: vrabaud

tests/CMakeLists.txt

@@ -176,6 +176,7 @@ if(AVIF_FUZZTEST)
     macro(add_avif_fuzztest TEST_NAME)
         add_executable(${TEST_NAME} gtest/${TEST_NAME}.cc ${ARGN})
         # FuzzTest bundles GoogleTest so no need to link to gtest librairies.
+        # avif_enable_warnings is not added because it triggers to many warnings in fuzztest.
         target_link_libraries(${TEST_NAME} PRIVATE avif_fuzztest_helpers aviftest_helpers_internal)
         link_fuzztest(${TEST_NAME})
         add_test(NAME ${TEST_NAME} COMMAND ${TEST_NAME} --stack_limit_kb=512)