feat: upgrade eslint to v9.15 (#603)

* feat: upgrade eslint to v9

* feat: remove deprecated eslintrc.json config

.nvmrc

@@ -1 +1 @@
-20.3.1
+20.18.0

eslint.config.js

@@ -0,0 +1,50 @@
+// @ts-check
+
+import eslint from '@eslint/js';
+import jestPlugin from 'eslint-plugin-jest';
+import globals from 'globals';
+import tseslint from 'typescript-eslint';
+
+export default tseslint.config(
+  {
+    ignores: ['**/coverage/**', '**/dist/**', '**/node_modules/**'],
+  },
+  {
+    extends: [
+      eslint.configs.recommended,
+      ...tseslint.configs.recommended,
+    ],
+    languageOptions: {
+      parser: tseslint.parser,
+      parserOptions: {
+        projectService: true,
+        tsconfigRootDir: import.meta.dirname,
+      },
+      globals: {
+        ...globals.jquery,
+        ...globals.browser,
+        ...globals.node,
+        ...globals.jest,
+      },
+    },
+    rules: {
+      '@typescript-eslint/no-unused-vars': 'off',
+      '@typescript-eslint/no-unused-expressions': 'off',
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-var-requires': 'warn',
+    },
+  },
+  {
+    // disable type-aware linting on JS files
+    files: ['**/*.js'],
+    ...tseslint.configs.disableTypeChecked
+  },
+  {
+    // enable jest rules on test files
+    files: ['**/*.test.{js,ts}'],
+    ...jestPlugin.configs['flat/recommended'],
+    rules: {
+      '@typescript-eslint/no-unsafe-argument': 'off',
+    },
+  },
+);