composer/package-versions-deprecated is a fully-compatible fork of ocramius/package-versions which provides compatibility with Composer 1 and 2 on PHP 7+. It replaces ocramius/package-versions so if you have a dependency requiring it and you want to use Composer v2 but can not upgrade to PHP 7.4 just yet, you can require this package instead.
If you have a direct dependency on ocramius/package-versions, we recommend instead that once you migrated to Composer 2 you also migrate to use the Composer\Versions class which offers the functionality present here out of the box.