Update PropertyGraph to not use deprecated cugraph features

[rlratzel]

Regular use of PropertyGraph results in the following warnings:

/home/user/.local/lib/python3.11/site-packages/cugraph/structure/symmetrize.py:260: FutureWarning: This method is deprecated and will no longer be supported. The symmetrization of the edges are only supported by setting the 'symmetrize' flag to 'True'
  warnings.warn(

/home/user/.local/lib/python3.11/site-packages/cugraph/structure/symmetrize.py:92: FutureWarning: Multi is deprecated and the removal of multi edges will no longer be supported from 'symmetrize'. Multi edges will be removed upon creation of graph instance.

This is the result of the PG code calling the deprecated symmetrize function.

PG should be updated to symmetrize (or drop duplicate edges) differently.