### 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, multimesh->buffer);
					for (uint32_t i = 0; i < visible_region_count; i++) {
						if (multimesh->data_cache_dirty_regions[i]) {
							GLint offset = i * region_size;
							GLint size = multimesh->stride_cache * (uint32_t)multimesh->instances * (uint32_t)sizeof(float);
							uint32_t region_start_index = multimesh->stride_cache * MULTIMESH_DIRTY_REGION_SIZE * i;
							glBufferSubData(GL_ARRAY_BUFFER, offset, MIN(region_size, size - offset), &data[region_start_index]);
						}
					}
					glBindBuffer(GL_ARRAY_BUFFER, 0);
				}
				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;
			}
			if (multimesh->aabb_dirty && multimesh->mesh.is_valid()) {
				_multimesh_re_create_aabb(multimesh, data, visible_instances);
				multimesh->aabb_dirty = false;
				multimesh->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_AABB);
			}
		}
		multimesh_dirty_list = multimesh->dirty_list;
		multimesh->dirty_list = nullptr;
		multimesh->dirty = false;
	}
	multimesh_dirty_list = nullptr;
}
RID MeshStorage::skeleton_allocate() {