### 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.
resource_conversion_plugins.push_back(orm_mat_convert);
		Ref<CanvasItemMaterialConversionPlugin> canvas_item_mat_convert;
		canvas_item_mat_convert.instantiate();
		resource_conversion_plugins.push_back(canvas_item_mat_convert);
		Ref<ParticleProcessMaterialConversionPlugin> particles_mat_convert;
		particles_mat_convert.instantiate();
		resource_conversion_plugins.push_back(particles_mat_convert);
		Ref<ProceduralSkyMaterialConversionPlugin> procedural_sky_mat_convert;
		procedural_sky_mat_convert.instantiate();
		resource_conversion_plugins.push_back(procedural_sky_mat_convert);
		Ref<PanoramaSkyMaterialConversionPlugin> panorama_sky_mat_convert;
		panorama_sky_mat_convert.instantiate();
		resource_conversion_plugins.push_back(panorama_sky_mat_convert);
		Ref<PhysicalSkyMaterialConversionPlugin> physical_sky_mat_convert;
		physical_sky_mat_convert.instantiate();
		resource_conversion_plugins.push_back(physical_sky_mat_convert);
		Ref<FogMaterialConversionPlugin> fog_mat_convert;
		fog_mat_convert.instantiate();
		resource_conversion_plugins.push_back(fog_mat_convert);
		Ref<VisualShaderConversionPlugin> vshader_convert;
		vshader_convert.instantiate();
		resource_conversion_plugins.push_back(vshader_convert);
	}
	update_spinner_step_msec = OS::get_singleton()->get_ticks_msec();
	update_spinner_step_frame = Engine::get_singleton()->get_frames_drawn();
	editor_plugin_screen = nullptr;
	editor_plugins_over = memnew(EditorPluginList);
	editor_plugins_force_over = memnew(EditorPluginList);
	editor_plugins_force_input_forwarding = memnew(EditorPluginList);
	Ref<GDExtensionExportPlugin> gdextension_export_plugin;