Make dry-run publish steps' labeling more explicit

From https://github.com/riseproject-dev/python-wheels/pull/204#discussion_r3734442848:

not strictly related to this PR, but what about having a ./.github/workflows/deploy.yml workflow that would contains this to avoid copying it in each individual workflow?

The other benefit is that inside this file we could do something like:

• name: Deploy${{ github.ref != 'refs/heads/main' && ' (dry run)' || '' }}
  uses: ./.github/actions/deploy
  with:
  dry-run: ${{ github.ref != 'refs/heads/main' }}

So the name of the job will actually contain "(dry run)" . Right now, we have the impression that the publish job succeeded and correctly uploaded file on the registry

Further deploy changes probably aren't worth the effort, but taking Julien's suggestion to make the dry-run labeling more explicit would be helpful for our PRs.

Überprüfe .github/workflows/deploy.yml und .github/actions/deploy sowie die Workflows, die derzeit die Deploy-Schritte wiederholen. Aktualisiere die Kennzeichnung des Veröffentlichungsschritts, sodass Probeläufe sichtbar markiert sind, und führe den betroffenen GitHub Actions-Workflow aus, um zu bestätigen, dass der Jobname vermittelt, dass kein tatsächlicher Upload erfolgt ist.