Update python-flit-core to version 3.7.1 / rev 9 via SR 964842
    
    https://build.opensuse.org/request/show/964842
    by user bnavigator + dimstar_suse
    - Update to version 3.7.1
      * Support for external data files such as man pages or Jupyter
        extension support files (PR #510).
      * Project names are now lowercase in wheel filenames and
        .dist-info folder names, in line with the specifications (PR
        #498).
      * Improved support for bootstrapping a Python environment, e.g.
        for downstream packagers (PR #511). flit_core.wheel is usable
        with python -m to create wheels before the build tool is
        available, and flit_core sdists also include a script to
        install itself from a wheel before installer is available.
      * Use newer importlib APIs, fixing some deprecation warnings (PR
        #499).
      * Fix building packages which need execution to get the version
        number, and have a relative import in __init__.py (PR #531).
    - Update b