Fixes missing actuator indices variable in joint randomization (#3447)

# Description

This PR fixes an issue introduced in #3251 , which accidentally deleted
actuator_indices in the case where `asset_cfg.joint_id` is not a `slice`
and `actuator.joint_indices` is a `slice`

## Type of change

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

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## Checklist

- [x] I have read and understood the [contribution
guidelines](https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html)
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- [ ] 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
- [x] I have updated the changelog and the corresponding version in the
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source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.46.1"
+version = "0.46.2"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+
+0.46.2 (2025-09-13)
+~~~~~~~~~~~~~~~~~~~
+
+Changed
+^^^^^^^
+
+* Fixed missing actuator indices in :meth:`~isaaclab.envs.mdp.events.randomize_actuator_gains`
+
+
 0.46.1 (2025-09-10)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/envs/mdp/events.py

@@ -602,7 +602,7 @@ class randomize_actuator_gains(ManagerTermBase):
                     raise TypeError("Actuator joint indices must be a slice or a torch.Tensor.")
             elif isinstance(actuator.joint_indices, slice):
                 # we take the joints defined in the asset config
-                global_indices = torch.tensor(self.asset_cfg.joint_ids, device=self.asset.device)
+                global_indices = actuator_indices = torch.tensor(self.asset_cfg.joint_ids, device=self.asset.device)
             else:
                 # we take the intersection of the actuator joints and the asset config joints
                 actuator_joint_indices = actuator.joint_indices