Fix release dry-run fails with a non-existing workflow

[FrankYang0529]

Why

• Basic tests / Test Airflow release commands has failed on every canary run of main on both AMD and ARM.
  • https://github.com/apache/airflow/actions/runs/30920541612/job/92029887148
  • https://github.com/apache/airflow/actions/runs/30946105312/job/92116499405
• Until Resolve the constraints a release ships instead of tagging whatever exists #71040, the constraints step of start-rc-process was tag_and_push_constraints(): a local git checkout, git tag and git push through run_command(). A dry run prints those and moves on.
• Resolve the constraints a release ships instead of tagging whatever exists #71040 replaced it with generate_and_push_constraints() → publish_constraints() → trigger_workflow_and_monitor(), which dispatches the release-constraints workflow and then has to locate the run it created and poll it to completion.
• run_gh_command() short-circuits a dry run: it returns a synthetic success with empty output.
• get_workflow_run_id() then goes looking for the run. The run_gh_command() short-circuits gh run list in the same way. The get_workflow_run_id() gets an empty string and exits 1 with "No workflow runs found."

How

• trigger_workflow_and_monitor() returns right after the dispatch in a dry run.

Verification

• uv run --project dev/breeze --frozen --no-sync pytest dev/breeze/tests/test_gh_workflow_utils.py dev/breeze/tests/test_release_constraints.py dev/breeze/tests/test_workflow_commands.py -v
• env CI=true GITHUB_REPOSITORY=apache/airflow breeze release-management start-rc-process --version 3.2.0rc1 --previous-version 3.1.0 --task-sdk-version 1.1.0rc1 --sync-branch v3-2-test --answer yes --dry-run

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Was generative AI tooling used to co-author this PR?

• Yes - Claude Code

---

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[github-actions]

Backport successfully created: v3-3-test

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
✅	v3-3-test