### Godot version

v4.2.beta1.official [b1371806a]

### System information

Ubuntu 22.04.3 LTS 22.04 - X11 - GLES3 (Compatibility) - AMD Radeon RX 560 Series (polaris11, LLVM 15.0.7, DRM 3.42, 5.15.0-88-generic) () - AMD Ryzen 3 1200 Quad-Core Processor (4 Threads)

### Issue description

![image](https://github.com/godotengine/godot/assets/1330325/7a986599-5a68-42a4-beb1-5d3b4bf7db6b)
![image](https://github.com/godotengine/godot/assets/1330325/e8b8546b-b47b-4add-9567-7f70709ab03c)

Culling 3D goes bellow 60 fps even with just about 50 simple animated models. With v4.2.dev6.official [57a6813bb] many more models can be spawned without fps drop. However, both versions do show high cpu usage for culling 3D. Without animations there's barely any usage.

### Steps to reproduce

Spawn models with animation with the Compatibility renderer.

### Minimal reproduction project

[CullMRP.zip](https://github.com/godotengine/godot/files/13400514/CullMRP.zip)

uint32_t region_index = p_index / MULTIMESH_DIRTY_REGION_SIZE;
#ifdef DEBUG_ENABLED
	uint32_t data_cache_dirty_region_count = (multimesh->instances - 1) / MULTIMESH_DIRTY_REGION_SIZE + 1;
	ERR_FAIL_UNSIGNED_INDEX(region_index, data_cache_dirty_region_count); 
#endif
	if (!multimesh->data_cache_dirty_regions[region_index]) {
		multimesh->data_cache_dirty_regions[region_index] = true;
		multimesh->data_cache_used_dirty_regions++;
	}
	if (p_aabb) {
		multimesh->aabb_dirty = true;
	}
	if (!multimesh->dirty) {
		multimesh->dirty_list = multimesh_dirty_list;
		multimesh_dirty_list = multimesh;
		multimesh->dirty = true;
	}
}
void MeshStorage::_multimesh_mark_all_dirty(MultiMesh *multimesh, bool p_data, bool p_aabb) {