Ai halts when Dreadhorde Butcher attacks

**Description**
Often, though not always, when Dreadhorde Butcher attacks, the Ai doesn't take an action (at least within ~5 mins nothing happens).

It's pretty consistent if deadhorde butcher is the only attacker and the Ai has only 1 untapped blocker.
If I have more than 1 attacker and the Ai choses not to block Dreadhorde Butcher, it doesn't always lock.

It's happened at least 3 times in the last hour for me.

**Notes**
The Ai is mad at skill 10.
I don't have a log of the game it seems, as the most recent one is a game that concluded, but some of the actions are visible in the attached screenshot.


Start by reproducing the described Dreadhorde Butcher attack with one untapped blocker and observe the attached screenshot and available game actions. Trace the AI's combat decision until the stall is found; done means the AI resolves the attack instead of waiting indefinitely.

Written by the indexing model from the issue text.