Update dependency eslint to v9 (#413)

* Update dependency eslint to v9

* use flat config file

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Scott Vandehey <[email protected]>

Author: renovate[bot]

__tests__/engines.test.mjs

@@ -1,3 +1,4 @@
+// eslint-disable-next-line n/no-unsupported-features/node-builtins
 import { describe, it } from 'node:test';
 import assert from 'node:assert/strict';
 import { execFileSync } from 'node:child_process';

__tests__/selector-bem-pattern/index.test.mjs

@@ -1,3 +1,4 @@
+// eslint-disable-next-line n/no-unsupported-features/node-builtins
 import { beforeEach, describe, it } from 'node:test';
 import assert from 'node:assert/strict';
 import { readFileSync } from 'node:fs';

eslint.config.mjs

@@ -0,0 +1,3 @@
+import stylelintConfig from 'eslint-config-stylelint';
+
+export default [...stylelintConfig];