Fix detecting of Apple Silicon architecture

On some Macs, Ruby reports the host CPU as "arm". Might be related to
which version of the kernel is installed, but uname still reports
"arm64".

Author: jacob-carlborg-apoex

exe/dartsass

@@ -10,7 +10,7 @@ platform_string = "#{system_config["host_cpu"]}-#{system_config["host_os"]}"
 exe_path =
   case platform_string
   when /aarch64-linux/ then File.join(__dir__, "aarch64-linux/sass")
-  when /arm64-darwin/ then File.join(__dir__, "arm64-darwin/sass")
+  when /arm(64)?-darwin/ then File.join(__dir__, "arm64-darwin/sass")
   when /darwin/ then File.join(__dir__, "darwin/sass")
   when /linux/ then File.join(__dir__, "linux/sass")
   when /mswin|mingw|cygwin/ then File.join(__dir__, "mingw32/sass.bat")