Varbase 9.2.1

Patch release for existing Varbase 9.2.x (Drupal ~11.4) sites.
Moves the Automated Functional Testing suites onto Varbase E2E
(@vardot/varbase-e2e ^2, Playwright + Cucumber-js) and clears the
PHPStan findings raised by the updated analyzers.

Plan: https://www.drupal.org/i/3616857