[WIP] Update to eslint 9

Close #843

eslint.config.mjs

@@ -0,0 +1,28 @@
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import js from "@eslint/js";
+import { FlatCompat } from "@eslint/eslintrc";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all
+});
+
+export default [{
+  ignores: [
+    "app/assets/config/manifest.js",
+    "app/assets/javascript/**/vendor/*.js",
+    "config/**/*.js",
+  ],
+}, ...compat.extends("neostandard"), {
+  settings: {
+    "import/resolver": {
+      node: {
+        paths: ["app/javascript"],
+      },
+    },
+  },
+}];

package.json

@@ -48,11 +48,11 @@
     "@babel/eslint-parser": "^7.25.7",
     "@types/express": "^5.0.0",
     "@webpack-cli/serve": "^2.0.4",
-    "eslint": "^8.57.1",
-    "eslint-config-standard": "^17.1.0",
+    "eslint": "^9.11.1",
+    "neostandard": "^0.11.6",
     "eslint-plugin-import": "^2.31.0",
-    "eslint-plugin-n": "^16.6.2",
-    "eslint-plugin-promise": "^6.6.0",
+    "eslint-plugin-n": "^17.10.3",
+    "eslint-plugin-promise": "^7.1.0",
     "eslint-webpack-plugin": "^4.2.0",
     "stylelint": "16.9.0",
     "stylelint-config-twbs-bootstrap": "^15.1.0",