[TiledFusedLogitsLoss] support inference (#7477)
Adding inference support for `TiledFusedLogitsLoss` by skipping
`backward` inside `forward` if the incoming tensor doesn't require grad.
xref: https://github.com/snowflakedb/ArcticTraining/pull/259
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Signed-off-by: Stas Bekman <stas@stason.org>
Co-authored-by: Rui Yan <49115835+yanrui27@users.noreply.github.com>
Co-authored-by: Olatunji Ruwase <tunji.ruwase@snowflake.com>
