fig.add_vline fails on figure with a separate subplot containing Scatter3d

The following code creates a 2D subplot in the left column and a 3D subplot in the right column. Adding a vertical line to the 2D subplot fails if a Scatter3d has been added to the 3D subplot.

Another bug shown in this example is that add_vline does not add any annotations if the plot is empty.

from plotly import subplots
specs = [
    [{}, {'type': 'scene', 'rowspan': 1}],
]
fig = subplots.make_subplots(rows=1, cols=2, specs=specs)

# Add dummy data 
# If both of these are commented out, fig.add_vline does nothing
# If neither are commented out, fig.add_vline raises a PlotlyKeyError
# If fig.add_scatter3d is commented out, the figure is generated successfully
fig.add_scatter(x=[0, 1], y=[0, 1], row=1, col=1)
fig.add_scatter3d(x=[0, 1], y=[0, 1], z=[0, 1], row=1, col=2)

# Add vertical line to left (2D) subplots only
fig.add_vline(x=2, col=1)  # Raises PlotlyKeyError

(Plotly version 5.9.0)

首先复现提供的 make_subplots、add_scatter3d 和 add_vline 示例，包括所展示的三种数据配置。跟踪 add_vline 的入口点及其对 2D 和 scene 子图的处理；当 2D 垂直线不再引发 PlotlyKeyError 且空图接收到注释时，即表示完成。