Bump mods/basic_materials from `9d55f99` to `b9ac857`
Bumps [mods/basic_materials](https://github.com/mt-mods/basic_materials) from `9d55f99` to `b9ac857`. - [Release notes](https://github.com/mt-mods/basic_materials/releases) - [Commits](https://github.com/mt-mods/basic_materials/compare/9d55f9916d20779ecbf93c7e95dae8adebd2079b...b9ac85790df6416085870d8acbb7eb4a3f5d4040)