The past few times I’ve run yay I’ve got these warnings about packages that are orphaned/not in the AUR. Based on the names I’m assuming these are leftover from the upgrade from kde plasma 5 to 6, are these safe to remove now? And secondly how would I find orphaned packages like that if I wasn’t using yay since I never installed these from the AUR?
In this context, orphaned doesn't always mean you should remove it. It just means that nobody in AUR is taking responsibility to keep it updated. You still might have other packages from the AUR that depend on this one.
Since it is unmaintained, basically anyone can now claim ownership of that package in the AUR and push updates for it. Theoretically, someone could try to distribute malware in this way.
This is why it's important to check the diffs of your AUR updates.
I never knowingly installed these, the only packages I’ve intentionally installed from the AUR are heroic games launcher and 7-zip. And the only kde programs I’ve manually installed is the plasma-meta package, kde connect and ksnip. I think they were previously part of the plasma-meta package and have now been removed or replaced with the plasma 6 versions
This is the case. You shouldn't have issues if you follow the instructions another comment had to replace the hotkey until
I just went for it and assumed the meta package was updated right and deleted the deprecated packages and had no issues