Summary

1. The change that broke[Bug]: title position incorrect for polar plot #29381 would have been fine if thelogic that calculatestop withinAxes._update_title_position only needed to work for ordinaryAxes instances.
2. Cartopy has artists separate from theXAxis andYAxis which must be considered for title placement. Currently, it does that byoverriding_update_title_position. Overriding a private method is not ideal, neither is repeating some of the code that is already in the parent method.

Proposed fix

Factor out a public method that returnstop. Making it public means it can safely be overridden in subclasses such asPolarAxes and Cartopy'sGeoAxes. Knowing it can/should be overridden in subclasses means that in the parentAxes we can use the most efficient approach that works forAxes.