Improves Kit load time with SurfaceGripper. (#483)

# Description

Improved Kit load time with SurfaceGripper by loading the extension only
if a SurfaceGripper is initialized.

## 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

apps/isaaclab.python.headless.kit

@@ -192,7 +192,6 @@ enabled=true # Enable this for DLSS
 "isaacsim.core.cloner" = {}
 "isaacsim.core.utils" = {}
 "isaacsim.core.version" = {}
-"isaacsim.robot.surface_gripper" = {}
 
 ########################
 # Isaac Lab Extensions #

apps/isaaclab.python.kit

@@ -27,7 +27,6 @@ keywords = ["experience", "app", "usd"]
 "isaacsim.robot.manipulators" = {}
 "isaacsim.robot.policy.examples" = {}
 "isaacsim.robot.schema" = {}
-"isaacsim.robot.surface_gripper" = {}
 "isaacsim.robot.wheeled_robots" = {}
 "isaacsim.sensors.camera" = {}
 "isaacsim.sensors.physics" = {}

source/isaaclab/isaaclab/assets/surface_gripper/surface_gripper.py

@@ -8,15 +8,19 @@ from __future__ import annotations
 import torch
 import warnings
 import weakref
+from typing import TYPE_CHECKING
 
 import omni.timeline
 from isaacsim.core.simulation_manager import IsaacEvents, SimulationManager
+from isaacsim.core.utils.extensions import enable_extension
 from isaacsim.core.version import get_version
-from isaacsim.robot.surface_gripper import GripperView
 
 import isaaclab.sim as sim_utils
 from isaaclab.assets import AssetBase
 
+if TYPE_CHECKING:
+    from isaacsim.robot.surface_gripper import GripperView
+
 from .surface_gripper_cfg import SurfaceGripperCfg
 
 
@@ -266,6 +270,9 @@ class SurfaceGripper(AssetBase):
             Use `--device cpu` to run the simulation on CPU.
         """
 
+        enable_extension("isaacsim.robot.surface_gripper")
+        from isaacsim.robot.surface_gripper import GripperView
+
         # Check that we are using the CPU backend.
         if self._device != "cpu":
             raise Exception(