### 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.
_notify_theme_override_changed();
		} else {
			return false;
		}
	} else {
		if (name.begins_with("theme_override_icons/")) {
			String dname = name.get_slicec('/', 1);
			add_theme_icon_override(dname, p_value);
		} else if (name.begins_with("theme_override_styles/")) {
			String dname = name.get_slicec('/', 1);
			add_theme_style_override(dname, p_value);
		} else if (name.begins_with("theme_override_fonts/")) {
			String dname = name.get_slicec('/', 1);
			add_theme_font_override(dname, p_value);
		} else if (name.begins_with("theme_override_font_sizes/")) {
			String dname = name.get_slicec('/', 1);
			add_theme_font_size_override(dname, p_value);
		} else if (name.begins_with("theme_override_colors/")) {
			String dname = name.get_slicec('/', 1);
			add_theme_color_override(dname, p_value);
		} else if (name.begins_with("theme_override_constants/")) {
			String dname = name.get_slicec('/', 1);
			add_theme_constant_override(dname, p_value);
		} else {
			return false;
		}
	}
	return true;
}
bool Window::_get(const StringName &p_name, Variant &r_ret) const {