Sets default clipping mode for cameras to None (#1559)

# Description

In https://github.com/isaac-sim/IsaacLab/pull/891, the
`depth_clipping_behavior` parameter was added with the default mode set
to `"zero"`. This introduced a breaking behavior in the depth cameras as
previously, values returned by the cameras were not clipped. This PR
sets the default behavior to `"none"`, which should bring us back to the
original camera behavior.

## Type of change

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applicable. -->

- 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
- [x] 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/extensions/omni.isaac.lab/omni/isaac/lab/sensors/camera/camera_cfg.py

@@ -53,8 +53,8 @@ class CameraCfg(SensorBaseCfg):
     asset is already present in the scene.
     """
 
-    depth_clipping_behavior: Literal["max", "zero", "none"] = "zero"
-    """Clipping behavior for the camera for values exceed the maximum value. Defaults to "zero".
+    depth_clipping_behavior: Literal["max", "zero", "none"] = "none"
+    """Clipping behavior for the camera for values exceed the maximum value. Defaults to "none".
 
     - ``"max"``: Values are clipped to the maximum value.
     - ``"zero"``: Values are clipped to zero.

source/extensions/omni.isaac.lab/omni/isaac/lab/sensors/ray_caster/ray_caster_camera_cfg.py

@@ -46,8 +46,8 @@ class RayCasterCameraCfg(RayCasterCfg):
     data_types: list[str] = ["distance_to_image_plane"]
     """List of sensor names/types to enable for the camera. Defaults to ["distance_to_image_plane"]."""
 
-    depth_clipping_behavior: Literal["max", "zero", "none"] = "zero"
-    """Clipping behavior for the camera for values exceed the maximum value. Defaults to "zero".
+    depth_clipping_behavior: Literal["max", "zero", "none"] = "none"
+    """Clipping behavior for the camera for values exceed the maximum value. Defaults to "none".
 
     - ``"max"``: Values are clipped to the maximum value.
     - ``"zero"``: Values are clipped to zero.