[Attributor] Disable three tests until the SCC update bug was fixed

D76588 exposed an SCC update bug in three tests which manifests
sometimes, e.g., on this bot that runs expensive checks:
  http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/23032/steps/test-check-all/logs/FAIL%3A%20LLVM%3A%3Afp80.ll

We disable the tests temporarily to investigate.