devel/gobject-introspection: update to 1.66.1

1.66.1 - 2020-10-03

• Update glib annotations
• Windows: Fix running on different drives [1]
• gimarshallingtests: Add more tests for flags [2]
• Revert "giscanner: Fix section matching for documentation [3] see [4]

[1] https://gitlab.gnome.org/GNOME/gobject-introspection/-/merge_requests/239
[2] https://gitlab.gnome.org/GNOME/gobject-introspection/-/merge_requests/235
[3] https://gitlab.gnome.org/GNOME/gobject-introspection/-/merge_requests/237
[4] https://gitlab.gnome.org/GNOME/gobject-introspection/-/issues/360