BUG: Adding offset produces NonExistentTimeError
In #36160, Travis had the following failure:

````
pandas/tests/tseries/offsets/test_offsets_properties.py:88: 
[snip]
---------------------------------- Hypothesis ----------------------------------
Falsifying example: test_on_offset_implementations(
    dt=datetime.datetime(1900, 1, 1, 0, 0, tzinfo=tzfile('/usr/share/zoneinfo/Iceland')),
    offset=<96 * MonthBegins>,
)
You can reproduce this example by temporarily adding @reproduce_failure('5.29.0', b'AAEAMgAAAAAAAAAAAABgAA==') as a decorator on your test case
````

Can reproduce with:

    from datetime import datetime
    import pytz
    from pandas.tseries.offsets import MonthBegin

    dt = datetime(1900, 1, 1, 0, 0, tzinfo=pytz.timezone('Iceland'))
    offset = MonthBegin(96)
    dt + offset

which produces the trace:

````
  File "pandas/_libs/tslibs/offsets.pyx", line 422, in pandas._libs.tslibs.offsets.BaseOffset.__add__
  File "pandas/_libs/tslibs/offsets.pyx", line 424, in pandas._libs.tslibs.offsets.BaseOffset.__add__
  File "pandas/_libs/tslibs/offsets.pyx", line 172, in pandas._libs.tslibs.offsets.apply_wraps.wrapper
  File "pandas/_libs/tslibs/timestamps.pyx", line 1317, in pandas._libs.tslibs.timestamps.Timestamp.tz_localize
  File "pandas/_libs/tslibs/tzconversion.pyx", line 63, in pandas._libs.tslibs.tzconversion.tz_localize_to_utc_single
  File "pandas/_libs/tslibs/tzconversion.pyx", line 319, in pandas._libs.tslibs.tzconversion.tz_localize_to_utc
pytz.exceptions.NonExistentTimeError: 1908-01-01 00:00:00
````

Not sure if this is a bug or an invalid input.