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 that once you migrated to Composer 2.x you also migrate to use the Composer\InstalledVersions class which offers the functionality present here out of the box. You can then remove the require on this package.
This package is EOL / deprecated and you should aim to migrate away from it as soon as possible!