python3Packages.slack-sdk: remove error message variations for "no internet connection"

  disabledTests = [

    # Requires internet access (to slack API)

    "test_start_raises_an_error_if_rtm_ws_url_is_not_returned"

    # Requires network access: [Errno 111] Connection refused

    "test_send_message_while_disconnection"

    # [Errno 61] Connection refused

    "TestWebClient_HttpRetry"

    # ConnectionResetError: [Errno 54] Connection reset by peer

    "test_issue_690_oauth_access"

    "test_issue_690_oauth_v2_access"

    "test_error_response"

    # Assertion Error: unexpectedly None (while accessing instance of slack store)

    "test_issue_1441_mixing_user_and_bot_installations"

  ];