### 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
state.instance_data_array[r_index].flags |= FLAGS_FLIP_V;
					}
					if (rect->flags & CANVAS_RECT_TRANSPOSE) {
						state.instance_data_array[r_index].flags |= FLAGS_TRANSPOSE_RECT;
					}
					if (rect->flags & CANVAS_RECT_CLIP_UV) {
						state.instance_data_array[r_index].flags |= FLAGS_CLIP_RECT_UV;
					}
				} else {
					dst_rect = Rect2(rect->rect.position, rect->rect.size);
					if (dst_rect.size.width < 0) {
						dst_rect.position.x += dst_rect.size.width;
						dst_rect.size.width *= -1;
					}
					if (dst_rect.size.height < 0) {
						dst_rect.position.y += dst_rect.size.height;
						dst_rect.size.height *= -1;
					}
					src_rect = Rect2(0, 0, 1, 1);
				}
				if (rect->flags & CANVAS_RECT_MSDF) {
					state.instance_data_array[r_index].flags |= FLAGS_USE_MSDF;
					state.instance_data_array[r_index].msdf[0] = rect->px_range; 
					state.instance_data_array[r_index].msdf[1] = rect->outline; 
					state.instance_data_array[r_index].msdf[2] = 0.f; 
					state.instance_data_array[r_index].msdf[3] = 0.f; 
				} else if (rect->flags & CANVAS_RECT_LCD) {
					state.instance_data_array[r_index].flags |= FLAGS_USE_LCD;
				}
				state.instance_data_array[r_index].modulation[0] = rect->modulate.r * base_color.r;