Optionally ignore utf-8 decoding error when converting std::string to python str. (#97282)
Summary: When language models use c++ tokenizer, outputs are a c++ strings that are not necessarily valid utf-8 encodings. Default pybind11 casting uses strict utf-8 decoding. We relax the decoding using 'ignore' argument.
Test Plan: https://www.internalfb.com/intern/testinfra/testrun/6473924609918070
Reviewed By: Nayef211
Differential Revision: D43970697
Pull Request resolved: https://github.com/pytorch/pytorch/pull/97282
Approved by: https://github.com/davidberard98
