### Godot version

v4.1.stable.official [970459615]  < Steam

### System information

Godot v4.1.stable - Debian GNU/Linux trixie/sid trixie - Vulkan (Mobile) - dedicated NVIDIA GeForce GTX 1060 (nvidia) - Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz (6 Threads)

### Issue description

After Godot got upgraded 4.0 -> 4.1, when opening a project from the earlier version, I noticed that the buttons in the confirmation dialog look a bit squiffy:

![Screenshot_20230706_123457](https://github.com/godotengine/godot/assets/441188/eb5dc8e3-9941-4cac-8cb8-17167d1f33bf)

(Somewhat aside, but that dialog should probably be able to deduce and be more precise about whether it's an upgrade or downgrade!)

### Steps to reproduce

1. Have a project from Godot 4.0
2. Upgrade Godot to 4.1
3. Open project manager

Alternatively:
1. Create a new project in 4.1
2. Quit Godot
3. Edit the `project.godot`'s `config/features` to read `4.0` instead of `4.1`
4. Open project manager

### Minimal reproduction project

[default.zip](https://github.com/godotengine/godot/files/11967512/default.zip)

Size2 dlg_size = get_size();
	float h_margins = theme_cache.panel_style->get_margin(SIDE_LEFT) + theme_cache.panel_style->get_margin(SIDE_RIGHT);
	float v_margins = theme_cache.panel_style->get_margin(SIDE_TOP) + theme_cache.panel_style->get_margin(SIDE_BOTTOM);
	
	bg_panel->set_position(Point2());
	bg_panel->set_size(dlg_size);
	
	Size2 buttons_minsize = buttons_hbox->get_combined_minimum_size();
	Size2 buttons_size = Size2(dlg_size.x - h_margins, buttons_minsize.y);
	Point2 buttons_position = Point2(theme_cache.panel_style->get_margin(SIDE_LEFT), dlg_size.y - theme_cache.panel_style->get_margin(SIDE_BOTTOM) - buttons_size.y);
	buttons_hbox->set_position(buttons_position);
	buttons_hbox->set_size(buttons_size);
	
	Point2 content_position = Point2(theme_cache.panel_style->get_margin(SIDE_LEFT), theme_cache.panel_style->get_margin(SIDE_TOP));
	Size2 content_size = Size2(dlg_size.x - h_margins, dlg_size.y - v_margins - buttons_size.y - theme_cache.buttons_separation);
	for (int i = 0; i < get_child_count(); i++) {
		Control *c = Object::cast_to<Control>(get_child(i));
		if (!c) {
			continue;
		}
		if (c == buttons_hbox || c == bg_panel || c->is_set_as_top_level()) {
			continue;
		}
		c->set_position(content_position);
		c->set_size(content_size);
	}
}
Size2 AcceptDialog::_get_contents_minimum_size() const {