### 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
GLES3::MeshStorage *mesh_storage = GLES3::MeshStorage::get_singleton();
			GLES3::ParticlesStorage *particles_storage = GLES3::ParticlesStorage::get_singleton();
			RID mesh;
			RID mesh_instance;
			uint32_t instance_count = 1;
			GLuint instance_buffer = 0;
			uint32_t instance_stride = 0;
			uint32_t instance_color_offset = 0;
			bool instance_uses_color = false;
			bool instance_uses_custom_data = false;
			bool use_instancing = false;
			if (state.canvas_instance_batches[p_index].command_type == Item::Command::TYPE_MESH) {
				const Item::CommandMesh *m = static_cast<const Item::CommandMesh *>(state.canvas_instance_batches[p_index].command);
				mesh = m->mesh;
				mesh_instance = m->mesh_instance;
			} else if (state.canvas_instance_batches[p_index].command_type == Item::Command::TYPE_MULTIMESH) {
				const Item::CommandMultiMesh *mm = static_cast<const Item::CommandMultiMesh *>(state.canvas_instance_batches[p_index].command);
				RID multimesh = mm->multimesh;
				mesh = mesh_storage->multimesh_get_mesh(multimesh);
				if (mesh_storage->multimesh_get_transform_format(multimesh) != RS::MULTIMESH_TRANSFORM_2D) {
					break;
				}
				instance_count = mesh_storage->multimesh_get_instances_to_draw(multimesh);
				if (instance_count == 0) {
					break;
				}
				instance_buffer = mesh_storage->multimesh_get_gl_buffer(multimesh);
				instance_stride = mesh_storage->multimesh_get_stride(multimesh);
				instance_color_offset = mesh_storage->multimesh_get_color_offset(multimesh);
				instance_uses_color = mesh_storage->multimesh_uses_colors(multimesh);