/usr/lib/x86_64-linux-gnu/libz3.so is in libz3-dev 4.4.0-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libz3.so.4
/usr/lib/x86_64-linux-gnu/libz3.so.4