[e2e] Disable Network for Puppeteer

In DevTools test we never use the Request part of Puppeteer,
as we don't read request or use Puppeteer network interception.
This means we are paying extra cost for having the domain enabled.
Testing the times for a small subset (test/e2e_non_hosted/elements/)
yielded 2.5% improvements on my CloudTop.

Bug: none
Change-Id: Ie046db3a60ea9437460332ae31828a1a01da78c8
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6787911
Reviewed-by: Alex Rudenko <[email protected]>
Reviewed-by: Liviu Rau <[email protected]>
Commit-Queue: Nikolay Vitkov <[email protected]>

Author: Lightning00Blade

test/e2e_non_hosted/shared/browser-helper.ts

@@ -64,6 +64,7 @@ export class Launcher {
       executablePath,
       dumpio: !headless || Boolean(process.env['LUCI_CONTEXT']),
       protocolTimeout,
+      networkEnabled: false,
     };
 
     TestConfig.configureChrome(executablePath);