DEV: Switch to use pnpm

.pnpmfile.cjs

@@ -0,0 +1,18 @@
+const fs = require("fs");
+const { execSync } = require("child_process");
+
+const currRoot = __dirname;
+
+if (fs.existsSync(`${currRoot}/node_modules/.yarn-integrity`)) {
+  console.log(
+    "Detected yarn-managed node_modules. Performing one-time cleanup..."
+  );
+
+  // Delete entire contents of all node_modules directories
+  // But keep the directories themselves, in case they are volume mounts (e.g. in devcontainer)
+  execSync(
+    `find ${currRoot}/node_modules -mindepth 1 -maxdepth 1 -exec rm -rf {} +`
+  );
+
+  console.log("cleanup done");
+}

package.json

@@ -5,5 +5,11 @@
     "ember-template-lint": "6.0.0",
     "eslint": "8.57.0",
     "prettier": "2.8.8"
+  },
+  "engines": {
+    "node": ">= 18",
+    "npm": "please-use-pnpm",
+    "yarn": "please-use-pnpm",
+    "pnpm": ">= 9"
   }
 }