DEV: Update eslint config (#8)

.eslintrc.cjs

-module.exports = require("@discourse/lint-configs/eslint-theme");

eslint.config.mjs

+import DiscourseRecommendedTheme from "@discourse/lint-configs/eslint-theme";
+
+export default [...DiscourseRecommendedTheme];

package.json

 {
   "private": true,
   "devDependencies": {
-    "@discourse/lint-configs": "1.4.2",
+    "@discourse/lint-configs": "2.0.1",
     "ember-template-lint": "6.0.0",
-    "eslint": "8.57.1",
-    "prettier": "2.8.8",
-    "@babel/plugin-proposal-decorators": "^7.25.7"
+    "eslint": "9.14.0",
+    "prettier": "2.8.8"
   },
   "engines": {
     "node": ">= 18",