interactive dataframe not displayed when column headers are numbers

### Versions
```
hvplot 0.8.1
panel 0.13.1
holoviews 1.15.1
pandas 1.5.0
numpy 1.22.4
python 3.9.13
jupyterlab 3.4.5

Chrome Browser
```

### Description
When trying to display an interactive dataframe with numbers as column headers, the result is no output. I have tested jupyterlab but not jupyter notebook.

### Code

```python
import pandas as pd
import numpy as np
import hvplot.pandas

df = pd.DataFrame(np.random.randn(10,10))
dfi = df.interactive(width=800, height=400)

# output works when changing the column headers to strings
# dfi = df.rename(columns=str).interactive(width=800, height=400)

dfi # no output
```

### Stack traceback and/or browser JavaScript console output
No error message

### Screenshot of bug

### Expected behavior