replacement for deprecated namespaces scipy.sparse.csc and scipy.sparse.csr

[quant12345]

This PR removes warnings:

DeprecationWarning: Please import `csr_matrix` from the `scipy.sparse` namespace; the `scipy.sparse.csr` namespace is deprecated and will be removed in SciPy 2.0.0.

DeprecationWarning: Please import `csc_matrix` from the `scipy.sparse` namespace; the `scipy.sparse.csc` namespace is deprecated and will be removed in SciPy 2.0.0.

Here and here (starting from line 75) there is information on this topic.

Tests to check:

pytest pandapower/test/loadflow/test_runpp_3ph.py
pytest pandapower/test/loadflow/test_runpp_3ph_n_line.py

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.00%. Comparing base (641134d) to head (41db0f5).
Report is 13 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #2372   +/-   ##
========================================
  Coverage    76.00%   76.00%           
========================================
  Files          282      282           
  Lines        32945    32945           
========================================
  Hits         25040    25040           
  Misses        7905     7905           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.