Bump mods/basic_materials from `8631a26` to `9d55f99`

Bumps [mods/basic_materials](https://github.com/mt-mods/basic_materials) from `8631a26` to `9d55f99`.
- [Release notes](https://github.com/mt-mods/basic_materials/releases)
- [Commits](https://github.com/mt-mods/basic_materials/compare/8631a2670bbca0bf8dbc5c128cdf8cde02fbda52...9d55f9916d20779ecbf93c7e95dae8adebd2079b)