I found the answer here: https://stackoverflow.com/a/78887005/5338948

The problem was that the ESLint docs don't specifically state that the ignores should be it's own object. I changed my eslint as below and it worked

import eslint from '@eslint/js';
import stylistic from '@stylistic/eslint-plugin';
import tseslint from 'typescript-eslint';

/** @type { import('@typescript-eslint/utils').TSESLint.FlatConfig.ConfigFile } */
export default [
  eslint.configs.recommended,
  ...tseslint.configs.recommendedTypeChecked,
  ...tseslint.configs.stylisticTypeChecked,

  stylistic.configs.customize({
    'indent': 2,
    'brace-style': '1tbs',
    'semi': true,
    'arrow-parens': true,
  }),
  {
    ignores: [
      '**/*.js',
      '**/tests-examples/**',
      '**/pw-report/**',
      'assets',
    ]
  },
  {
    plugins: {
      '@typescript-eslint': tseslint.plugin,
      '@stylistic': stylistic,
    },
...