Release: 0.12.1

[0.12.1] 2026-01-09

• [FIXED] phase shift transformers are now properly modeled
  for both pandapower (new in this version) and pypowsybl (already
  the case in previous version)
• [FIXED] a performance issue for all "XXXSingleSlack" (eg KLUSingleSlack) algorithm (filling of the initial
  Jacobian matrix was extremly slow due to the massive 'insert' of data in the eigen sparse matrix instead
  of relying on the "setFromTriplets" method)
• [FIXED] an normal "exception" was not catched in the close() method of LightSimBackend in case the
  backend was closed before any grid was loaded.
• [ADDED] possibility to pickle independantly all part of the grid (eg gridmodel.get_lines()
  can be pickled independantly from anything else) NB pickling and un-pickling
  lightsim2grid objects can only be used for the same lightsim2grid version.
• [ADDED] the init_from_n_powerflow property for ContingencyAnalysis (and
  ContingencyAnalysisCPP). It allows to chose if the computation of the contingencies
  are initialized with the complex voltages resulting of the powerflow in N
  (init_from_n_powerflow=True) or if they are initialized from the
  given input vector (init_from_n_powerflow=False). Defaults to False