### 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.
Ref<ConfigFile> cf;
	cf.instantiate();
	if (!DirAccess::exists(addon_path.get_base_dir())) {
		_remove_plugin_from_enabled(addon_path);
		WARN_PRINT("Addon '" + addon_path + "' failed to load. No directory found. Removing from enabled plugins.");
		return;
	}
	Error err = cf->load(addon_path);
	if (err != OK) {
		show_warning(vformat(TTR("Unable to enable addon plugin at: '%s' parsing of config failed."), addon_path));
		return;
	}
	if (!cf->has_section_key("plugin", "script")) {
		show_warning(vformat(TTR("Unable to find script field for addon plugin at: '%s'."), addon_path));
		return;
	}
	String script_path = cf->get_value("plugin", "script");
	Ref<Script> scr; 
	
	if (script_path.length() > 0) {
		script_path = addon_path.get_base_dir().path_join(script_path);
		scr = ResourceLoader::load(script_path, "Script", ResourceFormatLoader::CACHE_MODE_IGNORE);
		if (scr.is_null()) {
			show_warning(vformat(TTR("Unable to load addon script from path: '%s'."), script_path));
			return;
		}
		
		if (scr->get_instance_base_type() == StringName()) {
			if (_initializing_plugins) {