Fix docs. (#66383)

Fix docs. (#66383)

        * gtk/gtklabel.c: Fix docs. (#66383)

        * gtk/gtkbbox.c (gtk_button_box_set_child_secondary): Fix docs.
        (#66278, #66280)

        * gdk/gdkwindow.h (gdk_window_get_deskrelative_origin),
        gdk/gdkimage.h (gdk_image_get): Deprecate. (#66208)

        * gtk/gtkcolorsel.c (gtk_color_selection_set_update_policy):
        Don't emit a g_warning() about being deprecated. (#66208)

        * gtk/gtkaccellabel.c (gtk_accel_label_set_accel_widget): Add docs.

        * gtk/gtkcontainer.c: Doc fixes.

        * gtk/gtkliststore.c (gtk_list_store_clear): Add docs; misc doc fixes.

        * gtk/gtkstyle.c (gtk_style_attach): Add docs.

        * gdk-pixbuf.h (gdk_pixbuf_ref, gdk_pixbuf_unref,
        gdk_pixbuf_animation_ref, gdk_pixbuf_animation_unref):
        Deprecate. (#66208)

        * gtk/tmpl/gtklabel.sgml: Remove redundant docs. (#66383)

        * gtk/tree_widget.sgml: Typo fix. (#66256)

        * gdk-pixbuf/Makefile.am (SCAN_OPTIONS): Add --deprecated-guards.

        * gtk/tmpl/gtktext.sgml, gtk/tmpl/gtktree.sgml,
        gtk/tmpl/gtktreeitem.sgml: Updates.