### Godot version

4.1.1.stable, 4.2.dev (2282fc5de)

### System information

Arch Linux - X11 - GLES3 (Compatibility) - NVIDIA GeForce RTX 3060 Ti (nvidia; 535.104.05) - 13th Gen Intel(R) Core(TM) i5-13400F (16 Threads)

### Issue description

When using Compatibility renderer, adjusting the Alpha component of clear color affects 2D editor content.

This does not happen when using Forward+ or Mobile renderer. Does not affect 3D editor and the running game.


https://github.com/godotengine/godot/assets/372476/e398522e-590a-4832-959f-ea8ba8e71c5d



### Steps to reproduce

1. Create a project using Compatibility renderer.
2. Adjust the clear color's alpha component in Project Settings.

### Minimal reproduction project

N/A
_EIDX(2, 0), _EIDX(2, 1), _EIDX(3, 1),
			_EIDX(3, 1), _EIDX(3, 0), _EIDX(2, 0),
			_EIDX(2, 1), _EIDX(2, 2), _EIDX(3, 2),
			_EIDX(3, 2), _EIDX(3, 1), _EIDX(2, 1),
			_EIDX(2, 2), _EIDX(2, 3), _EIDX(3, 3),
			_EIDX(3, 3), _EIDX(3, 2), _EIDX(2, 2),
			
			_EIDX(1, 1), _EIDX(1, 2), _EIDX(2, 2),
			_EIDX(2, 2), _EIDX(2, 1), _EIDX(1, 1)
		};
#undef _EIDX
		glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(elems), elems, GL_STATIC_DRAW);
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
	}
	int uniform_max_size = config->max_uniform_buffer_size;
	if (uniform_max_size < 65536) {
		data.max_lights_per_render = 64;
	} else {
		data.max_lights_per_render = 256;
	}
	
	data.max_instances_per_buffer = uint32_t(GLOBAL_GET("rendering/gl_compatibility/item_buffer_size"));
	data.max_instance_buffer_size = data.max_instances_per_buffer * sizeof(InstanceData); 
	state.canvas_instance_data_buffers.resize(3);
	state.canvas_instance_batches.reserve(200);
	for (int i = 0; i < 3; i++) {
		GLuint new_buffers[3];
		glGenBuffers(3, new_buffers);