3D Skin Layers

What's Changed

• Add 1.21.10 support (also marked for 1.21.9, please update to 1.21.10, 1.21.9 is not supported)
• Update 1.21.6 -> 1.21.8 and 1.21 -> 1.21.1. This means the following versions are now unsupported: 1.21(.0), 1.21.6, 1.21.7
• Update es_ar.json by @Texaliuz in https://github.com/tr7zw/3d-Skin-Layers/pull/262

Full Changelog: https://github.com/tr7zw/3d-Skin-Layers/compare/1.9.0...1.9.1