Update /mnt path to use /Volume

[weilu]

https://github.com/dime-worldbank/mega-boost/blob/56e764c3840e06d71f31acf2a235568bffb5fc62/utils.py#L13C12-L13C46

This needs to be updated to /Volumes/prd_mega/sboost4/vboost4/Documents/input/Countries/