Adds gradient clipping parameter for distillation using RSL-RL (#2454)

# Description

Added `max_grad_norm` field to `RslRlDistillationAlgorithmCfg` in order
to be compatible with https://github.com/leggedrobotics/rsl_rl/pull/91

## Type of change

- New feature (non-breaking change which adds functionality)

## 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

---------
Signed-off-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>
Co-authored-by: alessandro.assirelli <alessandro.assirelli@agile-robots.com>
Co-authored-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>

CONTRIBUTORS.md

@@ -35,6 +35,7 @@ Guidelines for modifications:
 
 ## Contributors
 
+* Alessandro Assirelli
 * Alice Zhou
 * Amr Mousa
 * Andrej Orsula

source/isaaclab_rl/isaaclab_rl/rsl_rl/distillation_cfg.py

@@ -78,3 +78,6 @@ class RslRlDistillationAlgorithmCfg:
 
     gradient_length: int = MISSING
     """The number of environment steps the gradient flows back."""
+
+    max_grad_norm: None | float = None
+    """The maximum norm the gradient is clipped to."""

source/isaaclab_rl/setup.py

@@ -44,7 +44,7 @@ EXTRAS_REQUIRE = {
     "sb3": ["stable-baselines3>=2.1"],
     "skrl": ["skrl>=1.4.2"],
     "rl-games": ["rl-games==1.6.1", "gym"],  # rl-games still needs gym :(
-    "rsl-rl": ["rsl-rl-lib==2.3.1"],
+    "rsl-rl": ["rsl-rl-lib==2.3.3"],
 }
 # Add the names with hyphens as aliases for convenience
 EXTRAS_REQUIRE["rl_games"] = EXTRAS_REQUIRE["rl-games"]