You don't need to run Composer if you migrated to a higher PHP version, but it could give you access to a new version of some dependencies that are optimized for that new version.
If you do run Composer, don't run it withphp81 though ! Make sure the default command line version is also PHP 8.2 or run Composer with the PHP 8.2 executable (usually php8.2 or php82 on most systems).
