gh-137706: make typing._is_unpacked_typevartuple check for `True` instead of truthy#137712

JelleZijlstra merged 3 commits intopython:mainpython/cpython:mainfrom

DavidCEllis:fix-is-unpacked-typevartupleDavidCEllis/cpython:fix-is-unpacked-typevartupleCopy head branch name to clipboard