BUG: Timestamp.tz_localize inconsistent with pydatetime behavior

[jbrockmendel]

from pandas._libs.tslibs.conversion import localize_pydatetime
import pandas as pd
import pytz

ts = pd.Timestamp('2013-11-03 01:59:59.999999')
dt = ts.to_pydatetime()
tz = pytz.timezone("US/Eastern")

>>> localize_pydatetime(dt, tz)
datetime.datetime(2013, 11, 3, 1, 59, 59, 999999, tzinfo=<DstTzInfo 'US/Eastern' EST-1 day, 19:00:00 STD>)

>>> localize_pydatetime(ts, tz)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pandas/_libs/tslibs/conversion.pyx", line 629, in pandas._libs.tslibs.conversion.localize_pydatetime
    cpdef inline datetime localize_pydatetime(datetime dt, tzinfo tz):
  File "pandas/_libs/tslibs/conversion.pyx", line 645, in pandas._libs.tslibs.conversion.localize_pydatetime
    return dt.tz_localize(tz)
  File "pandas/_libs/tslibs/timestamps.pyx", line 2063, in pandas._libs.tslibs.timestamps.Timestamp.tz_localize
    value = tz_localize_to_utc_single(self.value, tz,
  File "pandas/_libs/tslibs/tzconversion.pyx", line 176, in pandas._libs.tslibs.tzconversion.tz_localize_to_utc_single
    return tz_localize_to_utc(
  File "pandas/_libs/tslibs/tzconversion.pyx", line 353, in pandas._libs.tslibs.tzconversion.tz_localize_to_utc
    raise pytz.AmbiguousTimeError(
pytz.exceptions.AmbiguousTimeError: Cannot infer dst time from 2013-11-03 01:59:59.999999, try using the 'ambiguous' argument

This can be wrapped in a user-facing example with DateOffset addition that I don't have on hand at the moment.

I expected the Timestamp behavior to match the datetime behavior.

[jbrockmendel]

Passing is_dst=None to tz_localize makes the first version raise, xref #55657