build: upgrade eslint to v9

eslint.config.js

@@ -0,0 +1,36 @@
+// @ts-check
+const eslint = require('@eslint/js');
+const tseslint = require('typescript-eslint');
+const angular = require('angular-eslint');
+
+module.exports = tseslint.config(
+  {
+    files: ['**/*.ts'],
+    extends: [eslint.configs.recommended, ...tseslint.configs.strict, ...angular.configs.tsRecommended],
+    processor: angular.processInlineTemplates,
+    rules: {
+      '@typescript-eslint/no-extraneous-class': 'off',
+      '@angular-eslint/directive-selector': [
+        'error',
+        {
+          type: 'attribute',
+          prefix: 'app',
+          style: 'camelCase',
+        },
+      ],
+      '@angular-eslint/component-selector': [
+        'error',
+        {
+          type: 'element',
+          prefix: 'app',
+          style: 'kebab-case',
+        },
+      ],
+    },
+  },
+  {
+    files: ['**/*.html'],
+    extends: [...angular.configs.templateRecommended, ...angular.configs.templateAccessibility],
+    rules: {},
+  },
+);