Adding PHP 8.2 in travis tests

Phew, getting php 8.2 working in my plugin’s travis tests required quite a bit of trial & error in travis.yaml, but 8 commits later I won 😉

The solution was in these extra lines to ensure libonig5 was installed;

  - dist: focal
    php: 8.2

  # for PHP 8.2 install libonig
  - if [ -n "$LIBONIG_INSTALL" ]; then sudo apt-get install libonig5; fi

Mastodon oEmbed requests overload; use WP Rest Cache

Mastodon due to the decentralized nature can result in a significant extra load on your site if someone posts a link to it. Every Mastodon instance where the post is seen (which can be 1 but also 100 or 1000 or …) will request not only the page and sub-sequentially the oEmbed json object to be able to show a preview in Mastodon. The page requests should not an issue as you surely have page caching, but the oEmbed object lives behind /wp-json/ and as such is not cached by page caches. The solution; the WP Rest Cache plugin and one small code snippet (for now). A lot more info can be found in Donncha’s excellent post on the subject.