[Test] Fixing issues related to `SampledHeteroCSC` and `StaticHeteroCSC` deprecation.

[drivanov]

trafficstars

Description

As we can see here:

test/nn/conv/cugraph/test_cugraph_rgcn_conv.py: 72 warnings
  /usr/local/lib/python3.10/dist-packages/pylibcugraphops/pytorch/graph.py:302: DeprecationWarning: SampledHeteroCSC is deprecated with the 23.08 release and will be removed in 23.10, use HeteroCSC instead.
    warnings.warn(
test/nn/conv/cugraph/test_cugraph_rgcn_conv.py: 72 warnings
  /usr/local/lib/python3.10/dist-packages/pylibcugraphops/pytorch/graph.py:330: DeprecationWarning: StaticHeteroCSC is deprecated with the 23.08 release and will be removed in 23.10, use HeteroCSC instead.
    warnings.warn(

the SampledHeteroCSC and StaticHeteroCSC classes were expected to be deprecated. Since pylibcugraphops-24.8 does not contain these classes, the examples/advanced/cugraph/rgcn.py test fails. That PR addresses this issue by implementing the necessary changes.

Checklist

Please feel free to remove inapplicable items for your PR.

• [x] The PR title starts with [$CATEGORY] (such as [NN], [Model], [Doc], [Feature]])
• [x] I've leverage the tools to beautify the python and c++ code.
• [x] The PR is complete and small, read the Google eng practice (CL equals to PR) to understand more about small PR. In DGL, we consider PRs with less than 200 lines of core code change are small (example, test and documentation could be exempted).
• [x] To the best of my knowledge, examples are either not affected by this change, or have been fixed to be compatible with this change

Changes