ci: update pdf text size
Created by: ashleythedeveloper
This PR adjusts the text size within the pdf derived from the website.
Note: There are h1 tags being misused on some of the pages, which will be rectified in another PR.
Example 1 (with h1 being misused)
Previous
New
Example 2
Previous
New
Artefact produced: un-transparency-protocol-new-text-size.pdf
Context: https://uncefact.slack.com/archives/C03L1LDU1ED/p1739249948701249