/usr/lib/gnu-smalltalk/gstopengl.so is in libgl-gst 3.2.5-1+b3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gnu-smalltalk/gstopengl-3.2.5.so
/usr/lib/gnu-smalltalk/gstopengl-3.2.5.so