I had a hack where I defaulted using get_supported_reso. But new pandas

also uses get_supported_reso when doing constructor with existing dtype.
This is missing things up. Only run the conversion if dtype is not good.
This only matters for [s]

pandas/core/construction.py

@@ -486,7 +486,11 @@ def ensure_wrapped_if_datetimelike(arr):
         if arr.dtype.kind == "M":
             from pandas.core.arrays import DatetimeArray
 
-            dtype = get_supported_dtype(arr.dtype)
+            dtype = arr.dtype
+            # get_supported_type is hacked to return [ms] instead of [s]
+            # I dont want this to change.
+            if not is_supported_dtype(dtype):
+                dtype = get_supported_dtype(dtype)
             return DatetimeArray._from_sequence(arr, dtype=dtype)
 
         elif arr.dtype.kind == "m":