Add release tag

With this MR, the runs hold information of the ocrd_all release that has triggered it by handing over the release tag from the web hook to the Quiver application.

The release information in the /runs end point is now structured as follows:

'release_info': {
        'id': int, # 12345678
        'url': str, # https://github.com/OCR-D/ocrd_all/releases/tag/v2023-12-07
        'tag': str, # v2023-12-12
        'date': str # 2023-12-08T12:08:39Z
    }