### Godot version

4.1.1

### System information

Meta Quest 2 - GLES3

### Issue description

When writing VR applications on Godot 4 using gl_compatibility, skeleton-driven meshes like hands are often rendered corrupted, or sometimes update slowly.

### Steps to reproduce

The godot-xr-tools demo projects have these issues in the climbing/gliding and pointer-demo scenes if the project is switched to gl_compatibility mode and run on a mobile VR headset.

### Minimal reproduction project

The godot-xr-tools demo project has been the testing project for this issue.
if (multimesh->data_cache.size() > 0 || multimesh->instances == 0) {
		return; 
	}
	ERR_FAIL_COND(multimesh->data_cache.size() > 0);
	
	
	multimesh->data_cache.resize(multimesh->instances * multimesh->stride_cache);
	{
		float *w = multimesh->data_cache.ptrw();
		if (multimesh->buffer_set) {
			Vector<uint8_t> buffer = Utilities::buffer_get_data(GL_ARRAY_BUFFER, multimesh->buffer, multimesh->instances * multimesh->stride_cache * sizeof(float));
			{
				const uint8_t *r = buffer.ptr();
				memcpy(w, r, buffer.size());
			}
		} else {
			memset(w, 0, (size_t)multimesh->instances * multimesh->stride_cache * sizeof(float));
		}
	}
	uint32_t data_cache_dirty_region_count = (multimesh->instances - 1) / MULTIMESH_DIRTY_REGION_SIZE + 1;
	multimesh->data_cache_dirty_regions = memnew_arr(bool, data_cache_dirty_region_count);
	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;
}
void MeshStorage::_multimesh_mark_dirty(MultiMesh *multimesh, int p_index, bool p_aabb) {