### Godot version

4.1.dev (dc625bcbfc5b587ba8867481ee7a1f6a567c25d0)

### System information

Mageia 9, Linux

### Issue description

When importing a project in current `master`, the following error is raised for each asset that gets imported:
```
Attempting to parent and popup a dialog that already has a parent.
```

It seems to be raised once per asset, caused by the progress dialog.

CC @bruvzg

### Steps to reproduce

- Import a new project in Godot that contains importable assets, e.g. https://github.com/RPicster/godot4-demo-desert-light

### Minimal reproduction project

See above.
if (theme_font_size_override.has(E)) {
				usage |= PROPERTY_USAGE_STORAGE | PROPERTY_USAGE_CHECKED;
			}
			p_list->push_back(PropertyInfo(Variant::INT, PNAME("theme_override_font_sizes") + String("/") + E, PROPERTY_HINT_RANGE, "1,256,1,or_greater,suffix:px", usage));
		}
	}
	{
		List<StringName> names;
		default_theme->get_icon_list(get_class_name(), &names);
		for (const StringName &E : names) {
			uint32_t usage = PROPERTY_USAGE_EDITOR | PROPERTY_USAGE_CHECKABLE;
			if (theme_icon_override.has(E)) {
				usage |= PROPERTY_USAGE_STORAGE | PROPERTY_USAGE_CHECKED;
			}
			p_list->push_back(PropertyInfo(Variant::OBJECT, PNAME("theme_override_icons") + String("/") + E, PROPERTY_HINT_RESOURCE_TYPE, "Texture2D", usage));
		}
	}
	{
		List<StringName> names;
		default_theme->get_stylebox_list(get_class_name(), &names);
		for (const StringName &E : names) {
			uint32_t usage = PROPERTY_USAGE_EDITOR | PROPERTY_USAGE_CHECKABLE;
			if (theme_style_override.has(E)) {
				usage |= PROPERTY_USAGE_STORAGE | PROPERTY_USAGE_CHECKED;
			}
			p_list->push_back(PropertyInfo(Variant::OBJECT, PNAME("theme_override_styles") + String("/") + E, PROPERTY_HINT_RESOURCE_TYPE, "StyleBox", usage));
		}
	}
}
void Window::_validate_property(PropertyInfo &p_property) const {