Update existing partition spec

[Laszlo Pinter]

Hi Iceberg Devs,

I'm using the Iceberg API to drop/add partition transforms, but recently
I've run into an issue.
When I try to add a new partition that previously existed, but it was
already dropped I get *Cannot use partition name more than once *error
message.

Here is what I'm doing:

table.updateSpec().addField(month("ts")).commit();
table.updateSpec().removeField("ts_month").commit();
table.updateSpec().addField(day("ts")).commit();
table.updateSpec().addField(month("ts")).commit();

What is the correct way to implement this sort of partition evolution?

Thanks,
Laszlo