[BUG]: last period label sometimes not drawn when using negative ticklabelindex

Here is an example of the last ticklabel not being drawn. The figure's ticklabelindex is set to -1:

Plotly 3.6.0 (missing last label)

Plotly 3.5.1 (all labels visible)

This is a regression from #7735. In version 3.5.1 ticklabelindex was ignored because no minor ticks were drawn. In version 3.6.0 ticklabelindex is not ignored and so for this figure, the label is expected to be drawn to the left of each major tick (ticklabelindex -1). However, there is no tick to the right of the last period and so that period is not labeled.

Before ticklabelindex, period labels were only ever drawn to the right of a major tick. There is logic in plotly to add a helper tick before the first period, making sure it will be labeled. For negative ticklabelindex, the same logic is required for the period at the end of the axis range.

Codepen: https://codepen.io/toffi-fee/pen/MYJEWLY

使用链接的 CodePen 重现缺失的标签，并比较 3.5.1 和 3.6.0 的行为。跟踪 ticklabelindex 的处理以及第一个周期现有的 helper-tick 逻辑，然后确保当索引为负数时，范围末端的等效情况会为最后一个周期添加标签。