### 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::Texture *texture = texture_storage->get_texture(ct->diffuse);
	Size2i size_cache;
	if (!texture) {
		ct->diffuse = texture_storage->texture_gl_get_default(GLES3::DEFAULT_GL_TEXTURE_WHITE);
		GLES3::Texture *tex = texture_storage->get_texture(ct->diffuse);
		size_cache = Size2i(tex->width, tex->height);
	} else {
		size_cache = Size2i(texture->width, texture->height);
	}
	GLES3::Texture *normal_map = texture_storage->get_texture(ct->normal_map);
	if (ct->specular_color.a < 0.999) {
		state.instance_data_array[r_index].flags |= FLAGS_DEFAULT_SPECULAR_MAP_USED;
	} else {
		state.instance_data_array[r_index].flags &= ~FLAGS_DEFAULT_SPECULAR_MAP_USED;
	}
	if (normal_map) {
		state.instance_data_array[r_index].flags |= FLAGS_DEFAULT_NORMAL_MAP_USED;
	} else {
		state.instance_data_array[r_index].flags &= ~FLAGS_DEFAULT_NORMAL_MAP_USED;
	}
	state.instance_data_array[r_index].specular_shininess = uint32_t(CLAMP(ct->specular_color.a * 255.0, 0, 255)) << 24;
	state.instance_data_array[r_index].specular_shininess |= uint32_t(CLAMP(ct->specular_color.b * 255.0, 0, 255)) << 16;
	state.instance_data_array[r_index].specular_shininess |= uint32_t(CLAMP(ct->specular_color.g * 255.0, 0, 255)) << 8;
	state.instance_data_array[r_index].specular_shininess |= uint32_t(CLAMP(ct->specular_color.r * 255.0, 0, 255));
	r_texpixel_size.x = 1.0 / float(size_cache.x);
	r_texpixel_size.y = 1.0 / float(size_cache.y);
	state.instance_data_array[r_index].color_texture_pixel_size[0] = r_texpixel_size.x;
	state.instance_data_array[r_index].color_texture_pixel_size[1] = r_texpixel_size.y;
}
void RasterizerCanvasGLES3::reset_canvas() {