/usr/lib/x86_64-linux-gnu/libamd.so is in libsuitesparse-dev 1:4.2.1-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libamd.so.2.3.1
/usr/lib/x86_64-linux-gnu/libamd.so.2.3.1