There is an updated pull request by daniel-eys against master on the void-packages repository

https://github.com/daniel-eys/void-packages python-sympy
https://github.com/void-linux/void-packages/pull/19987

python3-sympy: update to 1.5.1, drop python2
None

A patch file from https://github.com/void-linux/void-packages/pull/19987.patch is attached