Fixes for evaluation script (#509)

# Description

Minor fix to the evaluation script (robust_eval.py) to start evaluation
from the correct user-specified checkpoint.

## Type of change

- 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`
- [ ] 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
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

scripts/imitation_learning/robomimic/robust_eval.py

@@ -282,7 +282,7 @@ def main() -> None:
                 for model in model_checkpoints:
                     # Skip early checkpoints
                     model_epoch = int(model.split(".")[0].split("_")[-1])
-                    if model_epoch <= args_cli.start_epoch:
+                    if model_epoch < args_cli.start_epoch:
                         continue
 
                     model_path = os.path.join(args_cli.input_dir, model)