BUG: fix parquet roundtrip for Interval dtype with datetime64[ns] subtype
Closes #45881
thanks @jorisvandenbossche  Hi, is there a reason why this patch isn't included in pandas 1.4.x? I'm facing the same issue this PR was trying to address but I don't see the changes in the release. @jreback 

edit: I see, this is supposed to be included in the 1.5.0 release? we don't backport except regressions