### Godot version

v4.2.beta2.official [f8818f85e]

### System information

Windows 10, 64bit

### Issue description

Some times can't add node in visualshader editor

### Steps to reproduce

1. Open a VisualShader file for edit.
2. Click the `Add Node...` button, it will popup menu, it is OK.
3. Direct close the menu.
4. Clikd the `Add Node...` again, the menu can't popup.
![GIF](https://github.com/godotengine/godot/assets/35988767/1326c63e-3e05-4423-9ec7-7ce305b3f4f5)

### Minimal reproduction project

/
break;
				case VisualShader::VARYING_TYPE_INT:
					item->set_icon(0, EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("int"), EditorStringName(EditorIcons)));
					break;
				case VisualShader::VARYING_TYPE_UINT:
					item->set_icon(0, EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("uint"), EditorStringName(EditorIcons)));
					break;
				case VisualShader::VARYING_TYPE_VECTOR_2D:
					item->set_icon(0, EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Vector2"), EditorStringName(EditorIcons)));
					break;
				case VisualShader::VARYING_TYPE_VECTOR_3D:
					item->set_icon(0, EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Vector3"), EditorStringName(EditorIcons)));
					break;
				case VisualShader::VARYING_TYPE_VECTOR_4D:
					item->set_icon(0, EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Vector4"), EditorStringName(EditorIcons)));
					break;
				case VisualShader::VARYING_TYPE_BOOLEAN:
					item->set_icon(0, EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("bool"), EditorStringName(EditorIcons)));
					break;
				case VisualShader::VARYING_TYPE_TRANSFORM:
					item->set_icon(0, EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Transform3D"), EditorStringName(EditorIcons)));
					break;
				default:
					break;
			}
		}
	}
	varying_button->get_popup()->set_item_disabled(int(VaryingMenuOptions::REMOVE), count == 0);
}
void VisualShaderEditor::_varying_create() {