Data is available in Releases
Can be downloaded to a local mbtiles file by running the following commands
pip install pmtiles==3.2.0 mercantile==1.2.1 requests==2.30.0
python download_as_mbtiles.py
Data is also available as mvt tiles at -
https://indianopenmaps.fly.dev/google-buildings/{z}/{y}/{x}.pbf
Steps to reproduce what was done to get data in the current format are documented in steps.sh
Source: https://sites.research.google/open-buildings/
Changes Made: converted to pmtiles format, a tiny bit of data has been dropped( around 15% of 4 z14 tiles ) and some generalizations were applied at lower zoom levels.