Bump nvidia-nvjitlink-cu12 from 12.5.40 to 12.6.68

Bumps [nvidia-nvjitlink-cu12](https://developer.nvidia.com/cuda-zone) from 12.5.40 to 12.6.68.

---
updated-dependencies:
- dependency-name: nvidia-nvjitlink-cu12
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -48,7 +48,7 @@ nvidia-curand-cu12==10.3.7.37
 nvidia-cusolver-cu12==11.4.5.107
 nvidia-cusparse-cu12==12.1.0.106
 nvidia-nccl-cu12==2.20.5
-nvidia-nvjitlink-cu12==12.5.40
+nvidia-nvjitlink-cu12==12.6.68
 nvidia-nvtx-cu12==12.1.105
 omegaconf==2.3.0
 optuna==2.10.1