### 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::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
	if (p_texture == RID()) {
		p_texture = default_canvas_texture;
	}
	GLES3::CanvasTexture *ct = nullptr;
	GLES3::Texture *t = texture_storage->get_texture(p_texture);
	if (t) {
		
		if (!t->canvas_texture) {
			t->canvas_texture = memnew(GLES3::CanvasTexture);
			t->canvas_texture->diffuse = p_texture;
		}
		ct = t->canvas_texture;
	} else {
		ct = texture_storage->get_canvas_texture(p_texture);
	}
	if (!ct) {
		
		_prepare_canvas_texture(default_canvas_texture, p_base_filter, p_base_repeat, r_index, r_texpixel_size);
		return;
	}