using issue number from file for automated testing with latest issue

[joergi]

use output issue.txt for testing always with the latest version.

    - name: Download Issues with start and end limit
        id: normalIssuesWithRange
        run: bash ./linux_mac/magpi-issue-downloader.sh -f 94 -l 95

should become something like:

    - name: Download Issues with start and end limit
        id: normalIssuesWithRange
        run: bash ./linux_mac/magpi-issue-downloader.sh -f ($recent_issue - 1) -l $recent_issue

The normal recent_issue comes from this file, https://github.com/joergi/MagPiDownloader/blob/main/sources-for-download/regular-issues.txt