Trigger mt-sync-code-data.yml on new data download, not just outdated data

[Copilot]

mt-download-data.yml only triggered mt-sync-code-data.yml when deployed data was outdated (check_data_outdated.sh returned non-zero). This missed the case where download.sh fetched fresh data but the currently deployed data hadn't expired yet — MT_SKIP_PUSH_COMMIT=false signals this condition.

Change

• shared-overwrite/.github/workflows/mt-download-data.yml: Update trigger condition to skip sync only when both conditions are true: no new data was downloaded (MT_SKIP_PUSH_COMMIT==true) and data is not outdated (check_data_outdated.sh exits 0).

- name: MT check if data is outdated or new data downloaded & trigger sync
  run: |
    if [[ "${MT_SKIP_PUSH_COMMIT}" == true ]] && ./agency-parser/check_data_outdated.sh; then
      echo ">> No new data downloaded and data is up-to-date. No sync needed.";
    else
      echo ">> New data downloaded or data is outdated. Triggering mt-sync-code-data.yml workflow (skip download data)...";
      gh workflow run mt-sync-code-data.yml -f skip-download-data=true
    fi

MT_SKIP_PUSH_COMMIT is set by agency-parser/download.sh — defaults to true, set to false only when new GTFS archive data was committed.

[gemini-code-assist]

Code Review

This pull request modifies the mt-download-data.yml workflow to conditionally trigger a sync based on the MT_SKIP_PUSH_COMMIT variable and data freshness. Feedback includes improving the environment variable check to handle unset values and ensuring the triggered workflow targets the correct branch.