Quickly creating an issue for this; proper issue summary will follow.
https://www.drupal.org/docs/8/upgrade/upgrade-using-web-browser#pre-upgr...
If the database credentials to your source database are correct, the upgrade review page will appear as illustrated in the screenshot below. This page shows a summary of the upgrade status for all installed modules on the old site.
Latest iterations use this help text instead:
The new site is missing modules corresponding to the old site's modules. Unless they are installed prior to the upgrade, configuration and/or content needed by them will not be available on your new site. Read the checklist to help decide what to do.

Recent comments
Trying to push it to upstream 🤞 https://github.com/drush-ops/drush/pull/6621
Using Drush 8 with php 8
Wow, thank you!
Using Drush 8 with php 8
Hi folks, I went ahead and ported all drush 8.x stuff to PHP 8.3 and completely ripped out the legacy Symfony 2 internals. You can check out the exact details of what was done in the PR...
Using Drush 8 with php 8