/usr/lib/x86_64-linux-gnu/libicalss.so is in libical-dev 1.0.1-0ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libicalss.so.1
/usr/lib/x86_64-linux-gnu/libicalss.so.1