BUG: inconsistent behavior of DateOffset #47953
- [x] closes #47953
- [x] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/whatsnew/v2.0.3.rst` file if fixing a bug or adding a new feature.

thanks for your PR - looks like some tests are failing, could you fix them up please?
```
FAILED pandas/tests/tseries/offsets/test_offsets.py::test_dateoffset_add_sub[offset_kwargs0-1970-01-01 00:00:00.000000001] - AssertionError
FAILED pandas/tests/tseries/offsets/test_offsets.py::test_dateoffset_add_sub[offset_kwargs1-1970-01-01 00:00:00.000000005] - AssertionError
FAILED pandas/tests/tseries/offsets/test_offsets.py::test_dateoffset_add_sub[offset_kwargs2-1969-12-31 23:59:59.999999999] - AssertionError
FAILED pandas/tests/tseries/offsets/test_offsets.py::test_dateoffset_add_sub_timestamp_with_nano - AssertionError
``` I am looking into it. @MarcoGorelli the builds are passing now.  @MarcoGorelli can you please help me understand the next steps for this PR? I'll just leave this open a little to see if anyone else has comments/objections, and then will merge Hi @MarcoGorelli thanks for approving the PR. Any updates on this? TiA! right, let's ship this 🚀 