[gtkmm] Created tag 4.6.0

[Kjell Ahlstedt <kjellahl src gnome org>]

The unsigned tag '4.6.0' was created.

Tagger: Kjell Ahlstedt <kjellahlstedt gmail com>
Date: 1644406560 +0100

    4.6.0

Changes since the last tag '4.4.0':

Chun-wei Fan (2):
      build: Support Visual Studio 2022
      NMake Makefiles: Fix header installation

Kjell Ahlstedt (13):
      CI: Switching to debian:testing
      Gdk::Cairo: Ignore deprecation of gdk_cairo_draw_from_gl()
      Merge branch 'master' into 'master'
      Gdk::GLContext: Ignore deprecation of gdk_gl_context_set_use_es()
      Use gtk4 from the main branch in subproject
      Gdk::Device: Ignore deprecation of gdk_device_get_device_tool()
      CI: Don't build everything with warnings=fatal
      Gdk, Gtk: Regenerate docs.xml and .defs files
      Gdk::GLContext: Add API for version 4.6
      Gdk, Gtk: Add API for version 4.6
      CI: Switching to ubuntu:devel
      meson.build: Specify 'check' option in run_command()
      4.6.0

LI Daobing (1):
      Update object.h