returnCoordsPath is no longer defined here

[sprhawk]

https://github.com/drlukeparry/pyslm/blob/cc5417fa9b1e5cf78cf2a98ab45a144bb28906a0/pyslm/core.py#L567C12-L567C28

when running example_exporting_multilayer.py

[drlukeparry]

I can confirm this, which was unintentional in the dev branch on a recent commit. This will be resolved shortly.