Fix test_triangular_solve testcase enumeration (#67635)
Summary:
use product instead of zip to cover all cases
cc mruberry
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67635
Reviewed By: malfet
Differential Revision: D32310956
Pulled By: mruberry
fbshipit-source-id: 806c3313e2db26d77199d3145b2d5283b6ca3617
