Update for unicode fonts

Update for https://github.com/civicrm/civicrm-core/pull/31809 since there's no longer a need to install deja vu font separately in tarball installs. Also it seems an easier method of using cjk fonts has been available since dompdf 1.2.2.

It's a little hard to imagine what this looks like when rendered in the docs. Here's a screenshot when running mkdocs locally: