Fixes training parameter for Shadow Hand (#2421)

# Description

Fixes incorrect batch size for
Isaac-Repose-Cube-Shadow-OpenAI-FF-Direct-v0

## Type of change

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- Bug fix (non-breaking change which fixes an issue)


## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [ ] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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source/isaaclab_tasks/isaaclab_tasks/direct/shadow_hand/agents/rl_games_ppo_ff_cfg.yaml

@@ -79,7 +79,7 @@ params:
     bounds_loss_coef: 0.0001
 
     central_value_config:
-      minibatch_size: 32864
+      minibatch_size: 32768
       mini_epochs: 4
       learning_rate: 5e-4
       lr_schedule: adaptive