[BUG]Jumanji RWARE reward shape mismatch

[lbeyers]

We found that in the 4ag RWARE task, env.reward_spec().generate_value() gives something of shape (), but the reward that environment outputs is actually of shape (num_agents).

This is curious because I believe the scenario should output a reward of shape ().

Maybe it's a wrapper thing?

[sash-a]

Thanks Louise looks like this is a bug, we duplicated the reward and discount but never update the specs, my vote is to just not duplicate it and add a dummy agent dim so everything behaves the same.