Remove puppeteer

package.json

@@ -278,7 +278,6 @@
     "@web/dev-server": "^0.4.6",
     "@web/test-runner": "^0.18.3",
     "@web/test-runner-playwright": "^0.11.0",
-    "@web/test-runner-puppeteer": "^0.16.0",
     "clean-css": "^5.1.2",
     "codemirror": "^5.65.9",
     "codemirror-grammar-mode": "^0.1.10",

web-test-runner.config.js

@@ -5,7 +5,6 @@
  */
 
 import {playwrightLauncher} from '@web/test-runner-playwright';
-// import {puppeteerLauncher} from '@web/test-runner-puppeteer';
 import {fakeCdnPlugin} from './test/fake-cdn-plugin.js';
 import {startDevServer} from '@web/dev-server';
 
@@ -39,14 +38,6 @@ export default {
     playwrightLauncher({product: 'chromium'}),
     playwrightLauncher({product: 'webkit'}),
     playwrightLauncher({product: 'firefox'}),
-    // Playwright Firefox does not currently work with service workers, see
-    // https://github.com/microsoft/playwright/issues/7288.
-    //
-    // Also note we can't use Puppeteer for both Chromium and Firefox, because
-    // only one or the other can be installed at once (see our "postinstall" NPM
-    // script). See
-    // https://modern-web.dev/docs/test-runner/browser-launchers/puppeteer/.
-    // puppeteerLauncher({launchOptions: {product: 'firefox'}, concurrency: 1}),
   ],
   concurrentBrowsers: Number(process.env.CONCURRENT_BROWSERS) || 2, // default 2
   browserStartTimeout: 30000, // default 30000