2.89.0 (unstable) 2026-08-10

* Drop G_GNUC_CONST as in GLib.
  Merge request !77 (Sam James)

Glib:
* Markup::ParseContext: Add get_attribute_position().
  (Kjell Ahlstedt)

Gio:
* Emblem and DBus::ActionGroup: Don't derive gtkmm__Gxxx types.
  The underlying C classes are final types since GLib 2.89.2.
  (Kjell Ahlstedt)

Documentation:
* Remove duplicate of Glib::MarkupError documentation.
  (Kjell Ahlstedt)

Build:
* Require glib >= 2.89.0
  (Kjell Ahlstedt)