infra: migrate to eslint@9

eslint.config.js

@@ -0,0 +1,23 @@
+import { fixupPluginRules } from "@eslint/compat";
+import pluginJs from "@eslint/js";
+import configPrettier from "eslint-config-prettier";
+import pluginNoOnlyTests from "eslint-plugin-no-only-tests";
+import pluginTypescript from "typescript-eslint";
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  { ignores: ["dist/", "**/*.{js,mjs,cjs}"] },
+  pluginJs.configs.recommended,
+
+  ...pluginTypescript.configs.recommendedTypeChecked,
+  { languageOptions: { parserOptions: { projectService: true } } },
+
+  { plugins: { "no-only-tests": fixupPluginRules(pluginNoOnlyTests) } },
+  configPrettier,
+
+  {
+    rules: {
+      // "no-console": "error",
+    },
+  },
+];