on my mac upon running pulumi up for a typescript project I got the error Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.69.dylib .
Further digging I found this thread has the similar issue mentioned for a php issue https://stackoverflow.com/questions/53828891/dyld-library-not-loaded-usr-local-opt-icu4c-lib-libicui18n-62-dylib-error-run.
Solution Worked For me is :
brew reinstall icu4c