text: Title: Using a timestamp column for facet_col or facet_row gives a KeyError
  Body: Using a column which is a `datetime64[ns]` (e.g. what `pd.to_datetime()` or `pd.date_range()` returns) for `facet_col` or `facet_row` gives a key error.
  
  ```python
  import pandas as pd
  import numpy as np
  import plotly.express as px
  
  df = pd.DataFrame({'Cost': np.random.normal(size=20), 'Date': pd.date_range(start='2023-04-20', periods=20)})
  px.histogram(df, x='Cost',  facet_col='Date')
  ```
  This gives `KeyError: Timestamp('2023-04-20 00:00:00')`, as does `facet_row='Date'`.
  
  Converting the timestamp column to a string or a `datetime.date` (e.g. via `df['Date'].dt.date`) is a temporary workaround.