Update python-slack-sdk to version 3.26.2 / rev 9 via SR 1140323
    
    https://build.opensuse.org/request/show/1140323
    by user dirkmueller + anag+factory
    - update to 3.26.2:
      * #1447 #1446 aiohttp based socket_mode failed to reconnect and
        enter a broken state
      * #1436 Configuring with pyproject.toml
      * #1443 Update run_*.sh scripts to align with the contributor
      * #1445 Replace Flask-Sockets with aiohttp for testing
      * #1448 Fix broken links to modal documentation