### 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)

glBindBuffer(GL_ARRAY_BUFFER, 0);
	} else {
		
		ERR_FAIL_COND(p_buffer.size() != (multimesh->instances * (int)multimesh->stride_cache));
		const float *r = p_buffer.ptr();
		glBindBuffer(GL_ARRAY_BUFFER, multimesh->buffer);
		glBufferData(GL_ARRAY_BUFFER, p_buffer.size() * sizeof(float), r, GL_STATIC_DRAW);
		glBindBuffer(GL_ARRAY_BUFFER, 0);
	}
	multimesh->buffer_set = true;
	if (multimesh->data_cache.size() || multimesh->uses_colors || multimesh->uses_custom_data) {
		
		multimesh->data_cache = multimesh->data_cache;
		{
			
			uint32_t data_cache_dirty_region_count = (multimesh->instances - 1) / MULTIMESH_DIRTY_REGION_SIZE + 1;
			for (uint32_t i = 0; i < data_cache_dirty_region_count; i++) {
				multimesh->data_cache_dirty_regions[i] = false;
			}
			multimesh->data_cache_used_dirty_regions = 0;
		}
		_multimesh_mark_all_dirty(multimesh, false, true); 
	} else if (multimesh->mesh.is_valid()) {
		
		const float *data = p_buffer.ptr();
		_multimesh_re_create_aabb(multimesh, data, multimesh->instances);
		multimesh->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_AABB);
	}
}
Vector<float> MeshStorage::multimesh_get_buffer(RID p_multimesh) const {