Do I take two prize cards when a Pokemon-EX is discarded?
The wording on Cursed Shovel says

If the Pokémon this card is attached to is Knocked Out by damage from
an opponent’s attack, discard the top 2 cards of your opponent’s deck

Looking at The rules here for Pokémon-EX say

When one of your Pokémon-EX is Knocked Out, your opponent takes 2 Prize cards.

The appendix for 'knocked out' says

A Pokémon is Knocked Out if it has damage greater than or equal to its
Hit Points. That Pokémon goes to the discard pile along with all cards
attached to it. When one of your opponent’s Pokémon is Knocked Out,
take one of your Prize card

So you would not be entitled to take two prize cards.  You only take a prize card when you knock a Pokemon out.  Cursed shovel places Pokemon in the discard pile, it is not the same as 'knocking out' and would not give a prize at all.