ci: Change workflows to publish the snap to Store for Nvidia testing

[locnnil]

Add possibility to run nvidia workflow for artifacts of PRs and separate build and upload artifact on a dedicated workflow.

• Add: workflow to build and upload artifact
• Feat: Add possibility to run nvidia tests by passing the run-id of the wanted build workflow.

[hartmutobendorf]

sorry for causing confusion, the reference was meant to be to an issue, not this pr

[locnnil]

I suspect that the smoke-tests workflow isn’t being triggered because the “Build” workflow doesn’t exist in main branch.

[farshidtz]

Looks good. Thanks. Need to merge to test the workflow triggers.

[farshidtz]

The smoke test workflow fails during the artifact download step.
https://github.com/canonical/docker-snap/actions/runs/10555183107/job/29238305965

Run dawidd6/action-download-artifact@v6
  with:
    workflow: build.yml
    name: docker_[0-9]+.snap
    name_is_regexp: true
    github_token: ***
    workflow_search: false
    workflow_conclusion: success
    repo: canonical/docker-snap
    path: ./
    allow_forks: false
    check_artifacts: false
    search_artifacts: false
    skip_unpack: false
    if_no_artifact_found: fail
==> Repository: canonical/docker-snap
==> Artifact name: docker_[0-[9](https://github.com/canonical/docker-snap/actions/runs/10555183107/job/29238305965#step:3:9)]+.snap
==> Local path: ./
==> Workflow name: build.yml
==> Workflow conclusion: success
==> Allow forks: false
Error: Not Found - https://docs.github.com/rest/actions/workflow-runs#list-workflow-runs-for-a-workflow

Looks like it is can't find the workflow because the given workflow name (build.yml) doesn't match the actual name (build.yaml).