There's a merged pull request on the void-packages repository

python3-mpv: update to 1.0.3
https://github.com/void-linux/void-packages/pull/43720

Description:
Migrated from setuptools to pep517

#### Testing the changes
- I tested the changes in this PR: **NO** (not yet)

#### Local build testing
- I built this PR locally for my native architecture, (x86_64-glibc)