Dots Mesh now supports PHP 8

The latest web app version (v1.4.1) and the latest server version (v1.2.1) now support PHP 8. There are a few enhancements too. Check them out at the GitHub repositories:
github.com/dotsmesh/dotsmesh-web-app/releases/tag/v1.4.1
github.com/dotsmesh/dotsmesh-server-php/releases/tag/v1.2.1