Playwright 1.58 changed the output format of `npx playwright install --dry-run`:
- Old format: "browser: chromium version 143.0.7499.4"
- New format: "Chrome for Testing 145.0.7632.6 (playwright chromium v1208)"

Updated the regex to handle both formats while excluding chromium-headless-shell.

Fixes codeceptjs#5422

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Extract parsePlaywrightBrowsers function and add unit tests to verify
both old (Playwright < 1.58) and new (1.58+) output formats are parsed
correctly, and that chromium-headless-shell is excluded.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>