Fixes export LSTM to onnx file (#2821)

# Description

This PR fixes an issue when exporting LSTM to ONNX. The normalizer was
resetting to zero. This PR calls `eval()` during the `forward()`.

Fixes # (issue)

## Type of change

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applicable. -->

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

## Screenshots
Left: After, Right: Before


![image](https://github.com/user-attachments/assets/9a8f765f-653a-4a57-b9ee-af00e8e0539c)

## Checklist

- [ ] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [ ] 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_rl/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.1.6"
+version = "0.1.7"
 
 # Description
 title = "Isaac Lab RL"

source/isaaclab_rl/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.1.7 (2025-06-30)
+~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Call :meth:`eval` during :meth:`forward`` RSL-RL OnnxPolicyExporter
+
+
 0.1.6 (2025-06-26)
 ~~~~~~~~~~~~~~~~~~
 

source/isaaclab_rl/isaaclab_rl/rsl_rl/exporter.py

@@ -140,6 +140,7 @@ class _OnnxPolicyExporter(torch.nn.Module):
 
     def export(self, path, filename):
         self.to("cpu")
+        self.eval()
         if self.is_recurrent:
             obs = torch.zeros(1, self.rnn.input_size)
             h_in = torch.zeros(self.rnn.num_layers, 1, self.rnn.hidden_size)