/usr/lib/metis-long/libmetis.a is in libscotchmetis-dev 5.1.12b.dfsg-2build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/metis-long/libscotchmetis.a
/usr/lib/metis-long/libscotchmetis.a