op-challenger: Disable moves for permissioned games

[ajsutton]

op-challenger monitors permissioned games so it can resolve them and reclaim bonds. It also checks if it should perform moves even though it typically isn't the CHALLENGER and so its moves would be rejected. We could reduce the number of L1 RPC calls made significantly if the challenger only checked what steps to perform if it's tx sender was the authorised CHALLENGER role for permissioned games.

[ajsutton]

Need to check if this will actually help given that resolving the game requires resolving claims first so we may wind up loading the same data anyway.