Scatter matrix grid alignment with rotated X labels

When I rotate my X labels in a scatter matrix, the lower left panel does not seem to align correctly.

```
samples = 40
hvplot.scatter_matrix(pd.DataFrame({
'a':np.random.normal(0.5, 1, size=samples),
'b':np.random.normal(0.0,2.0, size=samples),
'c':np.random.normal(1e10,0.5e10,size=samples)}), xrotation=90)
```

hvplot = 0.7.3
holoviews = 1.14.5
bokeh = 2.3.3