[gnome-builder/wip/gtk4-port] plugins/debuggerui: remove border from notebook

[Christian Hergert <chergert src gnome org>]

commit c6f5d861e91c172f627f19405e92293857a6d33c
Author: Christian Hergert <chergert redhat com>
Date:   Sun May 8 14:25:00 2022 -0700

    plugins/debuggerui: remove border from notebook

 src/plugins/debuggerui/ide-debugger-workspace-addin.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/plugins/debuggerui/ide-debugger-workspace-addin.c 
b/src/plugins/debuggerui/ide-debugger-workspace-addin.c
index 8ab5ba102..4addba307 100644
--- a/src/plugins/debuggerui/ide-debugger-workspace-addin.c
+++ b/src/plugins/debuggerui/ide-debugger-workspace-addin.c
@@ -288,7 +288,9 @@ ide_debugger_workspace_addin_add_ui (IdeDebuggerWorkspaceAddin *self)
                                   NULL),
                     (IdePane **)&self->panel);
 
-  notebook = g_object_new (GTK_TYPE_NOTEBOOK, NULL);
+  notebook = g_object_new (GTK_TYPE_NOTEBOOK,
+                           "show-border", FALSE,
+                           NULL);
   panel_widget_set_child (PANEL_WIDGET (self->panel), GTK_WIDGET (notebook));
 
   hpaned = g_object_new (PANEL_TYPE_PANED,