Remove python 2 symbols, part of attempt at porting TFX to 3.12.4#240

pritamdodeja wants to merge 2 commits intogoogle:mastergoogle/ml-metadata:masterfrom

pritamdodeja:ml-metadata-py312-1.18dev-epritamdodeja/ml-metadata:ml-metadata-py312-1.18dev-eCopy head branch name to clipboard