Add cache hit test.

Add cache hit test for Cypress and Playwright.

   expect(await response.headerValue('X-Drupal-Cache') == 'HIT' ||
      await response.headerValue('X-Drupal-Dynamic-Cache') == 'HIT' ||
      await response.headerValue('X-Cache') == 'HIT' ||
      await response.headerValue('X-Varnish-Cache') == 'HIT').toBeTruthy();

h/t Petar Basic of Drunomics:
https://github.com/drunomics/playwright-drupal-starter/blob/main/tests/playwright/tests/helpers/test-methods.js