### Godot version

4.0 beta 17

### System information

Windows 10

### Issue description

Setting the color attribute in ParticleProcessMaterial for GPUParticles2D does not work with compatibility renderer
(works with forward+)

### Steps to reproduce

Set renderer to compatibility
Create a GPUParticles2D
Add ParticleProcessMaterial and set Color attribute (creating a particle shader and setting the `COLOR` is the same)


### Minimal reproduction project

[Particle2DColor.zip](https://github.com/godotengine/godot/files/10678236/Particle2DColor.zip)

state.instance_data_array[r_index].ninepatch_margins[1] = np->margin[SIDE_TOP];
				state.instance_data_array[r_index].ninepatch_margins[2] = np->margin[SIDE_RIGHT];
				state.instance_data_array[r_index].ninepatch_margins[3] = np->margin[SIDE_BOTTOM];
				_add_to_batch(r_index, r_batch_broken);
				
				state.instance_data_array[r_index].color_texture_pixel_size[0] = texpixel_size.x;
				state.instance_data_array[r_index].color_texture_pixel_size[1] = texpixel_size.y;
			} break;
			case Item::Command::TYPE_POLYGON: {
				const Item::CommandPolygon *polygon = static_cast<const Item::CommandPolygon *>(c);
				
				_new_batch(r_batch_broken);
				state.canvas_instance_batches[state.current_batch_index].tex = polygon->texture;
				state.canvas_instance_batches[state.current_batch_index].command_type = Item::Command::TYPE_POLYGON;
				state.canvas_instance_batches[state.current_batch_index].command = c;
				state.canvas_instance_batches[state.current_batch_index].shader_variant = CanvasShaderGLES3::MODE_ATTRIBUTES;
				_prepare_canvas_texture(polygon->texture, state.canvas_instance_batches[state.current_batch_index].filter, state.canvas_instance_batches[state.current_batch_index].repeat, r_index, texpixel_size);
				state.instance_data_array[r_index].modulation[0] = base_color.r;
				state.instance_data_array[r_index].modulation[1] = base_color.g;
				state.instance_data_array[r_index].modulation[2] = base_color.b;
				state.instance_data_array[r_index].modulation[3] = base_color.a;
				for (int j = 0; j < 4; j++) {
					state.instance_data_array[r_index].src_rect[j] = 0;
					state.instance_data_array[r_index].dst_rect[j] = 0;
					state.instance_data_array[r_index].ninepatch_margins[j] = 0;
				}
				_add_to_batch(r_index, r_batch_broken);
			} break;
			case Item::Command::TYPE_PRIMITIVE: {
				const Item::CommandPrimitive *primitive = static_cast<const Item::CommandPrimitive *>(c);