/usr/lib/libpanel-applet.so.0 is in libpanel-applet0 3.20.1-1+b2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libpanel-applet.so.0.1.0
/usr/lib/libpanel-applet.so.0.1.0