There is Leela Zero (https://github.com/leela-zero/leela-zero) for Go and lc0/Leela Chess (https://github.com/orgs/LeelaChessZero/repositories) for Chess, where both provide trained weights. The Leela Chess project specifically have been working for a long time on training and refining the weights for Chess, as well as providing the code -- they allow you to see the history and performance over time for the various trained models.