BUG: date_range fails when crossing DST boundary
- [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.

---

**Note**: Please read [this guide](https://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports) detailing how to provide the necessary information for us to reproduce your bug.

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

```python
import pandas as pd
pd.date_range('2020-03-09 00:00:00-07:00', '2021-03-09 00:00:00-08:00', tz='America/Los_Angeles')
...
TypeError: Start and end cannot both be tz-aware with different timezones
```

#### Problem description

The start and end timestamps in the above line of code are both valid timestamps in the `America/Los_Angeles` timezone, but they fail when passed directly

#### Expected Output

I would expect this to match the output from the following:
```
>>> pd.date_range('2020-03-09', '2021-03-09', freq='H', tz='America/Los_Angeles')
DatetimeIndex(['2020-03-09 00:00:00-07:00', '2020-03-09 01:00:00-07:00',
               '2020-03-09 02:00:00-07:00', '2020-03-09 03:00:00-07:00',
               '2020-03-09 04:00:00-07:00', '2020-03-09 05:00:00-07:00',
               '2020-03-09 06:00:00-07:00', '2020-03-09 07:00:00-07:00',
               '2020-03-09 08:00:00-07:00', '2020-03-09 09:00:00-07:00',
               ...
               '2021-03-08 15:00:00-08:00', '2021-03-08 16:00:00-08:00',
               '2021-03-08 17:00:00-08:00', '2021-03-08 18:00:00-08:00',
               '2021-03-08 19:00:00-08:00', '2021-03-08 20:00:00-08:00',
               '2021-03-08 21:00:00-08:00', '2021-03-08 22:00:00-08:00',
               '2021-03-08 23:00:00-08:00', '2021-03-09 00:00:00-08:00'],
              dtype='datetime64[ns, America/Los_Angeles]', length=8762, freq='H')
  ```

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

<details>

INSTALLED VERSIONS
------------------
commit           : f2c8480af2f25efdbd803218b9d87980f416563e
python           : 3.7.3.final.0
python-bits      : 64
OS               : Darwin
OS-release       : 19.6.0
Version          : Darwin Kernel Version 19.6.0: Mon Aug 31 22:12:52 PDT 2020; root:xnu-6153.141.2~1/RELEASE_X86_64
machine          : x86_64
processor        : i386
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 1.2.3
numpy            : 1.16.6
pytz             : 2020.1
dateutil         : 2.8.1
pip              : 20.2.4
setuptools       : 47.1.1
Cython           : 0.29.21
pytest           : 6.0.2
hypothesis       : None
sphinx           : None
blosc            : None
feather          : None
xlsxwriter       : 1.3.7
lxml.etree       : 4.5.2
html5lib         : None
pymysql          : None
psycopg2         : 2.8.4 (dt dec pq3 ext lo64)
jinja2           : 2.11.2
IPython          : None
pandas_datareader: None
bs4              : 4.9.1
bottleneck       : None
fsspec           : 0.7.4
fastparquet      : None
gcsfs            : 0.6.2
matplotlib       : 3.3.0
numexpr          : None
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : None
pyxlsb           : None
s3fs             : 0.4.2
scipy            : 1.5.2
sqlalchemy       : None
tables           : None
tabulate         : None
xarray           : None
xlrd             : 1.2.0
xlwt             : None
numba            : 0.50.1

</details>
