plotly 6.1.2 not showing datetime for FigureWidget

The FigureWidget seems to be broken in plotly 6.0 when showing datetime types.

Reproduced using the example [here](https://plotly.com/python/time-series/#time-series-using-axes-of-type-date)

```python
import plotly.graph_objects as go

import pandas as pd
df = pd.read_csv('https://raw.usercontent.com/plotly/datasets/master/finance-charts-apple.csv').assign(Date=lambda x: pd.to_datetime(x.Date))

fig = go.Figure([go.Scatter(x=df['Date'], y=df['AAPL.High'])])
fig.show()
```

displays correctly with datetime:

<img width="1342" alt="Image" src="https://.com/user-attachments/assets/2b7e4323-43d5-48f1-99b7-435b910dc86d" />

With FigureWidget:

```python
import plotly.graph_objects as go

import pandas as pd
df = pd.read_csv('https://raw.usercontent.com/plotly/datasets/master/finance-charts-apple.csv').assign(Date=lambda x: pd.to_datetime(x.Date))

fig = go.FigureWidget([go.Scatter(x=df['Date'], y=df['AAPL.High'])])
fig.show()
```

shows the nanosecond ints:

<img width="689" alt="Image" src="https://.com/user-attachments/assets/39fec134-b6cc-4518-9a4d-17b398d2b352" />

This was run in VSCode (1.100.2) and also jupyterlab/server (lab == 4.4.3, jupyter-server == 2.16.0)

Seems similar to #5101.

Description