Move OSX package task into build script

This is to match how the other binaries are built. Also made some
changes to make the Docker containers clean up for when you are running
this locally.

build/tasks.ts

@@ -21,6 +21,8 @@ const buildServerBinary = register("build:server:binary", async (runner) => {
 	logger.info("Building with environment", field("env", {
 		NODE_ENV: process.env.NODE_ENV,
 		VERSION: process.env.VERSION,
+		OSTYPE: process.env.OSTYPE,
+		TARGET: process.env.TARGET,
 	}));
 
 	await ensureInstalled();