pandas: BUG: pd.array([timedelta_like_strings]) should infer TimedeltaArray

>>> left = pd.array(['59 days', '59 days', pd.NaT]))
>>> left
<StringArray>
['59 days', '59 days', <NA>]
Length: 3, dtype: string

>>> left = pd.array(['59 days', '59 days', pd.NaT], dtype='m8[ns]')
>>> left
<TimedeltaArray>
['59 days', '59 days', NaT]
Length: 3, dtype: timedelta64[ns]