Make a new Github issue when a nightly run fails

[danielhollas]

We're running nightly tests periodically once per day:

aiida-core/.github/workflows/nightly.yml

Line 5 in 0eb77b8

- cron: 0 0 * * * # Run every day at midnight

When the workflow fails, the failure is posted in the aiida-core-dev Slack channel.

There are several issues with this:

1. The Slack channel is not public and easy to miss (as we discussed with @GeigerJ2 during coding week, people were generally not aware of it).
2. It's hard to track, discuss and resolve the failures in a consistent manner.

Instead of posting to a Slack channel, I would propose that failing workflow would automatically create Github issue. That might be noisy at fist, but it would force us to deal with the issues transparently.

The implementation of this is actually quite simple, I took this idea from the ruff repository:
https://github.com/astral-sh/ruff/blob/d0b2bbd55ee6435bc3dad8db2898aec216d85121/.github/workflows/daily_fuzz.yaml#L60

  create-issue-on-failure:
    name: Create an issue if the daily fuzz surfaced any bugs
    runs-on: ubuntu-latest
    needs: fuzz
    if: ${{ github.repository == 'astral-sh/ruff' && always() && github.event_name == 'schedule' && needs.fuzz.result == 'failure' }}
    permissions:
      issues: write
    steps:
      - uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            await github.rest.issues.create({
              owner: "astral-sh",
              repo: "ruff",
              title: `Daily parser fuzz failed on ${new Date().toDateString()}`,
              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
              labels: ["bug", "parser", "fuzzer"],
            })

CC @unkcpz @agoscinski