Bump rake-compiler/rake-compiler-dock-image from 1.3.0-mri-aarch64-linux to 1.3.1-mri-aarch64-linux in /docker

Bump rake-compiler/rake-compiler-dock-image from 1.3.0-mri-aarch64-linux to 1.3.1-mri-aarch64-linux in /docker #420