gtk: fix build on debian 12

src/apprt/gtk/Window.zig

@@ -1083,6 +1083,8 @@ fn gtkTitlebarMenuActivate(
     _: *c.GParamSpec,
     ud: ?*anyopaque,
 ) callconv(.C) void {
+    // debian 12 is stuck on GTK 4.8
+    if (!version.atLeast(4, 10, 0)) return;
     const active = c.gtk_menu_button_get_active(btn) != 0;
     const self = userdataSelf(ud orelse return);
     if (active) {

src/build/docker/debian/Dockerfile

@@ -10,6 +10,7 @@ RUN DEBIAN_FRONTEND="noninteractive" apt-get -qq update && \
     libonig-dev \
     lintian \
     lsb-release \
+    libxml2-utils \
     pandoc \
     wget \
     # Ghostty Dependencies