I did a fresh install of PostgreSQL 13.2 from EDB yesterday on Windows and discovered that the bundled pgAdmin was at version 4.30. I completely understand that the version bundled with the database may lag releases.
It can indeed. I believe the team are working on the 5.x update though.
I was wondering, though, about the correct way to install the newest version in that scenario. The EDB installer doesn't seem to let me separately uninstall pgAdmin or separately upgrade it. If I download and install v 5.1 from the pgAdmin site, will I end up having two versions installed?
It should let you uninstall components - run the uninstaller and it should ask what components to remove. Even if you remove everything, it won't touch your data directory so you can uninstall and then reinstall safely anyway.
If you install the community pgAdmin package it will install alongside the one with the database server; they should coexist without any problems. One won't attempt to modify the other in any way (unless you try to force the installation directory to be the same of course).