/usr/include/gimp-2.0/libgimpconfig/ is in libgimp2.0-dev 2.8.10-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gimp-2.0/libgimpconfig/gimpcolorconfig-enums.h
/usr/include/gimp-2.0/libgimpconfig/gimpcolorconfig.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig-deserialize.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig-error.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig-iface.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig-params.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig-path.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig-serialize.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig-utils.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfig.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfigtypes.h
/usr/include/gimp-2.0/libgimpconfig/gimpconfigwriter.h
/usr/include/gimp-2.0/libgimpconfig/gimpscanner.h