Backport PR #55761 on branch 2.1.x (BUG: DatetimeIndex.diff raising TypeError)
@mroeschke - were you planning to backport anything from #55524? It looks like some of the failures here (in 2.1.x) could use some of the updates you made in that PR. 

e.g `test_parse_tz_aware` is failing due to a units mismatch and it looks like you added an explicit cast to nanoseconds in that PR:

https://github.com/pandas-dev/pandas/blob/32b8cd2c81108dc51d59d2d09287df29d40d255b/pandas/tests/io/parser/test_parse_dates.py#L1005

 Ah I see. Definitely should not backport the dependency bumps, but potentially 2.1.x might not have pyarrow pinned like the main branch was and some of these code changes could be ported over there. 

But the failures are not related to this change right? > But the failures are not related to this change right?

Correct, the failures look unrelated 
