ci: add ccache hit-rate warning when < 75%

Print the ccache hit-rate for the job using a GitHub annotation if it
was below 75%.

ci/test/00_setup_env_mac_native_fuzz.sh

@@ -6,6 +6,7 @@
 
 export LC_ALL=C.UTF-8
 
+export CONTAINER_NAME="ci_mac_native_fuzz"  # macos does not use a container, but the env var is needed for logging
 export CMAKE_GENERATOR="Ninja"
 export BITCOIN_CONFIG="-DBUILD_FOR_FUZZING=ON -DCMAKE_EXE_LINKER_FLAGS='-Wl,-stack_size -Wl,0x80000'"
 export CI_OS_NAME="macos"