Update test_MaxUnpool_index_errors XFAIL after #107483 (#107658)
After https://github.com/pytorch/pytorch/pull/107483 which reverted https://github.com/pytorch/pytorch/pull/95300, these tests are not XFAIL anymore. So now we know the root cause of https://github.com/pytorch/pytorch/issues/103854.
As this is failing slow jobs in trunk atm, i.e. https://hud.pytorch.org/pytorch/pytorch/commit/6981bcbc35603e5d8ac7d00a2032925239009db5, I'm moving these tests back.
### Testing
Run locally and all tests passes.
```
PYTORCH_TEST_WITH_SLOW=1 PYTORCH_TEST_SKIP_FAST=1 python test/nn/test_pooling.py -k test_MaxUnpool_index_errors
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/107658
Approved by: https://github.com/PaliC
