id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
1646566213,I_kwDOAMm_X85iJJtF,7699,drop_sel returns KeyError for abbreviated dates,3924836,open,0,,,1,2023-03-29T21:31:40Z,2023-03-30T01:05:58Z,,MEMBER,,,,"### What happened?

for a dataframe with a detailed timestamp coordinate (`2022-03-11T13:50:50.551314000`)

`da.sel(time=""2022-03-11"")` works but da.drop_sel(time=""2022-03-11"") results in a `KeyError`

### What did you expect to happen?

i expect `drop_sel()` to work with the same inputs as `sel()`

### Minimal Complete Verifiable Example

```Python
import numpy as np
import xarray as xr
times = np.array(['2022-03-03T13:50:49.548072000', '2022-03-11T13:50:50.551314000',
                  '2022-03-12T13:44:35.547024000', '2022-03-13T12:18:48.015182000'],
                  dtype='datetime64[ns]')

da = xr.DataArray(np.arange(4), dims=""time"", coords={""time"": times})
da.drop_sel(time='2022-03-11')
```

A workaround is to use the exact datestring:
```
da.drop_sel(time='2022-03-11T13:50:50.551314000')
```


### MVCE confirmation

- [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
- [X] Complete example — the example is self-contained, including all data and the text of any traceback.
- [X] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result.
- [X] New issue — a search of GitHub Issues suggests this is not a duplicate.

### Relevant log output

```Python
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
Cell In[4], line 1
----> 1 da.drop_sel(time='2022-03-11')

File ~/.local/envs/xvec/lib/python3.11/site-packages/xarray/core/dataarray.py:3105, in DataArray.drop_sel(self, labels, errors, **labels_kwargs)
   3102 if labels_kwargs or isinstance(labels, dict):
   3103     labels = either_dict_or_kwargs(labels, labels_kwargs, ""drop"")
-> 3105 ds = self._to_temp_dataset().drop_sel(labels, errors=errors)
   3106 return self._from_temp_dataset(ds)

File ~/.local/envs/xvec/lib/python3.11/site-packages/xarray/core/dataset.py:5292, in Dataset.drop_sel(self, labels, errors, **labels_kwargs)
   5290     except KeyError:
   5291         raise ValueError(f""dimension {dim!r} does not have coordinate labels"")
-> 5292     new_index = index.drop(labels_for_dim, errors=errors)
   5293     ds = ds.loc[{dim: new_index}]
   5294 return ds

File ~/.local/envs/xvec/lib/python3.11/site-packages/pandas/core/indexes/base.py:6934, in Index.drop(self, labels, errors)
   6932 if mask.any():
   6933     if errors != ""ignore"":
-> 6934         raise KeyError(f""{list(labels[mask])} not found in axis"")
   6935     indexer = indexer[~mask]
   6936 return self.delete(indexer)

KeyError: ""['2022-03-11'] not found in axis""
```


### Anything else we need to know?

related to https://github.com/pydata/xarray/issues/6605#issuecomment-1126139617

### Environment

(xarray: 2023.3.0)

<details>


INSTALLED VERSIONS
------------------
commit: None
python: 3.11.0 | packaged by conda-forge | (main, Jan 14 2023, 12:27:40) [GCC 11.3.0]
python-bits: 64
OS: Linux
OS-release: 5.4.231-137.341.amzn2.x86_64
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: en_US.UTF-8
LANG: en_US.UTF-8
LOCALE: ('en_US', 'UTF-8')
libhdf5: 1.12.2
libnetcdf: 4.9.1

xarray: 2023.3.0
pandas: 1.5.3
numpy: 1.24.2
scipy: 1.10.1
netCDF4: 1.6.3
pydap: None
h5netcdf: 1.1.0
h5py: 3.8.0
Nio: None
zarr: None
cftime: 1.6.2
nc_time_axis: None
PseudoNetCDF: None
rasterio: 1.3.6
cfgrib: None
iris: None
bottleneck: None
dask: None
distributed: None
matplotlib: 3.7.1
cartopy: None
seaborn: None
numbagg: None
fsspec: None
cupy: None
pint: None
sparse: None
flox: None
numpy_groupies: None
setuptools: 67.6.0
pip: 23.0.1
conda: None
pytest: None
mypy: None
IPython: 8.11.0
sphinx: None

</details>
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