Switch to sync-message-port

package.json

@@ -10,6 +10,6 @@
     "chokidar": "^4.0.0",
     "immutable": "^4.0.0",
     "intercept-stdout": "^0.1.2",
-    "sass-embedded": "latest"
+    "sync-message-port": "v1.1.1"
   }
 }

package/package.json

@@ -19,7 +19,8 @@
   "dependencies": {
     "chokidar": "^4.0.0",
     "immutable": "^4.0.0",
-    "source-map-js": ">=0.6.2 <2.0.0"
+    "source-map-js": ">=0.6.2 <2.0.0",
+    "sync-message-port": "^1.1.1"
   },
   "optionalDependencies": {
     "@parcel/watcher": "^2.4.1"

tool/grind.dart

@@ -47,8 +47,7 @@ void main(List<String> args) {
     pkg.JSRequire("stream", target: pkg.JSRequireTarget.node),
     pkg.JSRequire("util", target: pkg.JSRequireTarget.node),
     pkg.JSRequire("worker_threads", target: pkg.JSRequireTarget.cli),
-    pkg.JSRequire("./sync-message-port.js",
-        target: pkg.JSRequireTarget.cli, identifier: 'sync_message_port'),
+    pkg.JSRequire("sync-message-port", target: pkg.JSRequireTarget.cli),
   ];
   pkg.jsModuleMainLibrary.value = "lib/src/js.dart";
   pkg.npmPackageJson.fn = () =>
@@ -135,8 +134,6 @@ void main(List<String> args) {
 
   afterTask("pkg-npm-dev", _addDefaultExport);
   afterTask("pkg-npm-release", _addDefaultExport);
-  afterTask("pkg-npm-dev", _addSyncMessagePort);
-  afterTask("pkg-npm-release", _addSyncMessagePort);
 
   grind(args);
 }
@@ -309,12 +306,6 @@ function defaultExportDeprecation() {
   File("build/npm/sass.node.mjs").writeAsStringSync(buffer.toString());
 }
 
-/// After building the NPM package, copy the sync-message-port.js from sass-embedded
-void _addSyncMessagePort() {
-  File("node_modules/sass-embedded/dist/lib/src/sync-process/sync-message-port.js")
-      .copy("build/npm/sync-message-port.js");
-}
-
 /// A regular expression to locate the language repo revision in the Dart Sass
 /// Homebrew formula.
 final _homebrewLanguageRegExp = RegExp(