Revert "[CI] limit number of threads on gb200" (#6820)

Reverts triton-lang/triton#6816

Author: ThomasRaoux

.github/workflows/integration-tests-nvidia.yml

@@ -93,7 +93,6 @@ jobs:
         run: |
           if [ "${{ matrix.runner[0] }}" == "nvidia-gb200" ]; then
             source /venv/bin/activate
-            export MAX_JOBS=16
           fi
           nproc
           nvidia-smi