[torchlib] Improve `EXPECTED_SKIPS_OR_FAILS` authoring experience

[BowenBao]

We author the skip list manually by hand. It would be nicer to have automated/semi-automated skip list population process to ease the experience as we expand the subtest size with allowing more datatypes.

cc @justinchuby, @titaiwangms

[justinchuby]

We should do this. We can then remove the allow list #784

[BowenBao]

Per offline discussion, looking at prototyping a generator tool for subtest xfail list.

[justinchuby]

Marking as low priority as we have enabled more of the data types in test