Removes isaaclab.controller import of Pink IK to prevent pinocchio import error (#3292)

# Description

Feature introduced in #3149 imports pink_ik for isaaclab.controller
module. This is causing an error IsaacLab wide due to pinocchio import.
This PR removes the import.

Fixes # (issue)
Fixed pinocchio import error due to isaaclab.controller module importing
pink_ik by default.

## Type of change

<!-- As you go through the list, delete the ones that are not
applicable. -->

- Breaking change (fix or feature that would cause existing
functionality to not work as expected)


## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] 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
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.45.8"
+version = "0.45.9"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.45.9 (2025-08-27)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed removing import of pink_ik controller from isaaclab.controllers which is causing pinocchio import error.
+
+
 0.45.8 (2025-07-25)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/controllers/__init__.py

@@ -15,4 +15,3 @@ from .differential_ik import DifferentialIKController
 from .differential_ik_cfg import DifferentialIKControllerCfg
 from .operational_space import OperationalSpaceController
 from .operational_space_cfg import OperationalSpaceControllerCfg
-from .pink_ik import NullSpacePostureTask, PinkIKController, PinkIKControllerCfg