ci: add npu on device

[fiskrt]

Add a NPU CI

Compliments the current CI pipeline which runs on every commit (even outside of main branch and in PRs) with a NPU CI which only runs when a commit is pushed to branch main and takes approx 25 mins.

Runs inside of a docker image called pto-dsl-ci:{hash of dockerfile} so it caches image.

Once inside the docker, it runs:

python -m pip install --no-cache-dir -e .
python -c "import torch; print(torch.ones(2).npu())"
pytest -v
python examples/validate_all_examples.py

TODO:

• add icon in readme that shows if NPU tests are green/red
• Improve docker run settings

[MirkoDeVita98]

nice, we can also setup a bot (e.g. renovate) that autobumps version of ptoas, commit of pto-isa in the CI yml file, creates a PR and runs tests. That to ensure w always have latest upated ptoas verified with npu tests/examples and we do not have to manually do it in each PR.