BUG: Resampling a Series with a DST to 24 hours gives a different result depending on whether timedelta(hours=24) or "24H" was used.
- [X] I have checked that this issue has not already been reported.

- [X] I have confirmed this bug exists on the latest version of pandas.

- [ ] (optional) I have confirmed this bug exists on the master branch of pandas.

---

#### Code Sample, a copy-pastable example

```python

>>> import pandas as pd
>>> from datetime import timedelta

>>> # works as expected given a DST (second index is 24 hours after the first index)
>>> pd.Series(1, index=pd.date_range("2020-03-29", "2020-03-30 01:00", freq="H", tz="Europe/Amsterdam")).resample("24H").asfreq()

2020-03-29 00:00:00+01:00    1
2020-03-30 01:00:00+02:00    1
Freq: 24H, dtype: int64

>>> # works, but not as expected (second index is 23 hours after the first index)
>>> pd.Series(1, index=pd.date_range("2020-03-29", "2020-03-30 01:00", freq="H", tz="Europe/Amsterdam")).resample(timedelta(hours=24)).asfreq()

2020-03-29 00:00:00+01:00    1
2020-03-30 00:00:00+02:00    1
Freq: D, dtype: int64

```

#### Problem description

Resampling to a timedelta of 24 hours gives a result as if it's resampling to a timedelta of 1 calendar day. Using a `freq_str` of 24H does give the expected behaviour.

Possibly related issues:

- #22864
- #35219

#### Expected Output

```python

>>> pd.Series(1, index=pd.date_range("2020-03-29", "2020-03-30 01:00", freq="H", tz="Europe/Amsterdam")).resample(timedelta(hours=24)).asfreq()

2020-03-29 00:00:00+01:00    1
2020-03-30 01:00:00+02:00    1
Freq: 24H, dtype: int64

```

#### Output of ``pd.show_versions()``

<details>

INSTALLED VERSIONS
------------------
commit           : None
python           : 3.7.7.final.0
python-bits      : 64
OS               : Linux
OS-release       : 4.9.0-11-amd64
machine          : x86_64
processor        : 
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8
pandas           : 1.0.5
numpy            : 1.19.0
pytz             : 2020.1
dateutil         : 2.8.1
pip              : 20.1.1
setuptools       : 47.3.1.post20200622
Cython           : None
pytest           : None
hypothesis       : None
sphinx           : None
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : None
html5lib         : None
pymysql          : None
psycopg2         : None
jinja2           : None
IPython          : None
pandas_datareader: None
bs4              : None
bottleneck       : None
fastparquet      : None
gcsfs            : None
lxml.etree       : None
matplotlib       : None
numexpr          : None
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : None
pytables         : None
pytest           : None
pyxlsb           : None
s3fs             : None
scipy            : None
sqlalchemy       : None
tables           : None
tabulate         : None
xarray           : None
xlrd             : None
xlwt             : None
xlsxwriter       : None
numba            : None

</details>
