Swap out `ml/json-ld` dependency with one that is maintained (required for PHP 8.4)

[GuySartorelli]

ml/json-ld hasn't been updated for 3 years and may have been abandoned. The PR for PHP 8.4 compatibility has gone unmerged for many months.

This means anyone running embed/embed with PHP 8.4 will get deprecation warnings, even though embed/embed itself is completely compatible with PHP 8.4. In the future things could start breaking outright.

I recommend finding a maintained alternative for the ml/json-ld dependency.