Saved layouts should work for more than one keyboard product id

[mxmilkiib]

I upgraded my Thumbsup v9 keyboard microchip from the Promicro to RP2040.

Now there is a different keyboard definition json file.

But I have a layout saved under the old chip that I want to reflash to the board, but this is not possible.

The layout has not changed at all, just the chip.

As the layout has not changed, the save of the old layout should be made available to be loaded while using the new product id.