Merge pull request #312203 from Kernald/keyfinder-cli-darwin

keyfinder-cli: add darwin as supported platform

pkgs/applications/audio/keyfinder-cli/default.nix

···
       used to estimate the musical key of many different audio formats.
     '';
     license = licenses.gpl3Plus;
-    platforms = platforms.linux;
+    platforms = platforms.unix;
     mainProgram = "keyfinder-cli";
   };
 }