### 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

/
switch (visual_shader->get_mode()) {
		case Shader::MODE_CANVAS_ITEM:
		case Shader::MODE_SPATIAL: {
			r_begin_type = 0;
			r_end_type = 3;
		} break;
		case Shader::MODE_PARTICLES: {
			r_begin_type = 3;
			r_end_type = 5 + r_begin_type;
		} break;
		case Shader::MODE_SKY: {
			r_begin_type = 8;
			r_end_type = 1 + r_begin_type;
		} break;
		case Shader::MODE_FOG: {
			r_begin_type = 9;
			r_end_type = 1 + r_begin_type;
		} break;
		default: {
		} break;
	}
}
void VisualShaderEditor::_script_created(const Ref<Script> &p_script) {