Targets the hand pitch links instead of roll links in GR1 IK controller. (#356)

# Description

The roll link parents the pitch link, so in the current configuration,
the controller is not able to control the pitch link. By targeting the
pitch link, the entire wrist can be controlled.

- 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`
- [x] 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

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/pickplace_gr1t2_env_cfg.py

@@ -219,14 +219,14 @@ class ActionsCfg:
             show_ik_warnings=False,
             variable_input_tasks=[
                 FrameTask(
-                    "GR1T2_fourier_hand_6dof_left_hand_roll_link",
+                    "GR1T2_fourier_hand_6dof_left_hand_pitch_link",
                     position_cost=1.0,  # [cost] / [m]
                     orientation_cost=1.0,  # [cost] / [rad]
                     lm_damping=10,  # dampening for solver for step jumps
                     gain=0.1,
                 ),
                 FrameTask(
-                    "GR1T2_fourier_hand_6dof_right_hand_roll_link",
+                    "GR1T2_fourier_hand_6dof_right_hand_pitch_link",
                     position_cost=1.0,  # [cost] / [m]
                     orientation_cost=1.0,  # [cost] / [rad]
                     lm_damping=10,  # dampening for solver for step jumps