### Godot version

v4.0.beta12.official [3c9bf4bc2]

### System information

Windows 10, AMD Radeon RX 480 4 GB RAM, 16 gb ram, Intel CPU 4 cores.

### Issue description


When switching to mobile render from forward + The alpha texture on the tree mesh starts to flicker.
Made a video: https://www.youtube.com/watch?v=WdGVi1hdRHo



### Steps to reproduce

Switching to mobile render from forward +

### Minimal reproduction project

Uploaded the project in google link: https://drive.google.com/file/d/1efEV914CWkyWoGzkv3RBMnw9t-4BVTeQ/view?usp=sharing
(only deleted the .godot - i guess its not needed.)
if (shadow_rect.intersects_transformed(F->xform_cache, F->aabb_cache)) {
						F->next = occluders;
						occluders = F;
					}
				}
			}
			
			RendererCanvasRender::Light *light = lights_with_shadow;
			while (light) {
				RENDER_TIMESTAMP("Render PointLight2D Shadow");
				RSG::canvas_render->light_update_shadow(light->light_internal, shadow_count++, light->xform_cache.affine_inverse(), light->item_shadow_mask, light->radius_cache / 1000.0, light->radius_cache * 1.1, occluders);
				light = light->shadows_next_ptr;
			}
			RENDER_TIMESTAMP("< Render PointLight2D Shadows");
		}
		if (directional_lights_with_shadow) {
			
			RendererCanvasRender::Light *light = directional_lights_with_shadow;
			while (light) {
				Vector2 light_dir = -light->xform_cache.columns[1].normalized(); 
				float cull_distance = light->directional_distance;
				Vector2 light_dir_sign;
				light_dir_sign.x = (ABS(light_dir.x) < CMP_EPSILON) ? 0.0 : ((light_dir.x > 0.0) ? 1.0 : -1.0);
				light_dir_sign.y = (ABS(light_dir.y) < CMP_EPSILON) ? 0.0 : ((light_dir.y > 0.0) ? 1.0 : -1.0);
				Vector2 points[6];
				int point_count = 0;
				for (int j = 0; j < 4; j++) {
					static const Vector2 signs[4] = { Vector2(1, 1), Vector2(1, 0), Vector2(0, 0), Vector2(0, 1) };
					Vector2 sign_cmp = signs[j] * 2.0 - Vector2(1.0, 1.0);
					Vector2 point = clip_rect.position + clip_rect.size * signs[j];