- Remove https://matplotlib.org/3.9.3/gallery/scales/log_bar.html
  The only scale-related aspect of the example is `ax.set_yscale("log")`.
  That's not something we need an extra example for. The scale works for
  all data content. We don't need to show that it also works for bars.
  Even worse, the example creates grouped bars, which require extra code
  and therefore distract from the scale aspect.
- Rename some example titles "Demo" -> "scale"