You can’t. This has been requested before (here for instance: FR: Number layouts sequentially regardless of type)
In the meantime, either put up with both being numbered 01 until they’ve been exported, then manually renumber, or manually renumber to a high number rather than insisting on 0. For instance, on a recent orchestra+choir piece I went with 01-whatever for part layouts, 100 for Full Score, 101 for Choral Score, 102 for Piano-Vocal Score etc.