Update python-networkx to version 2.6.1 / rev 30 via SR 909685
    
    https://build.opensuse.org/request/show/909685
    by user dirkmueller + RBrownSUSE
    - require pandas
    
    - update to 2.6.2:
      * This release is the result of 11 months of work with over 363 pull requests by
        91 contributors. Highlights include:
      * Dropped support for Python 3.6.
      * NumPy, SciPy, Matplotlib, and pandas are now default requirements.
      * NetworkX no longer depends on the library "decorator".
      * Improved example gallery
      * Removed code for supporting Jython/IronPython
      * The __str__ method for graph objects is more informative and concise.
      * Improved import time
      * Improved test coverage
      * New documentation theme
      * Add functionality for drawing self-loop edges
      * Add approximation algorithms for Traveling Salesman Problem
    - drop 0001-Replace-hash-function-for-test-of-weighted-astar.patch,
      yaml-loader.patch (merged upstream)