Can you please update the manifest cache and check if that fixes the problem?

I'm not even sure if that works anyway. As the foreach is not done by reference and the $extension var is not used any more.

some extensions have "false/null" in the manifest_cache field of the #__extensions table like mod_submenu

so unable to get the version from a null field/registry
https://github.com/joomla/joomla-cms/blob/4.0-dev/administrator/components/com_joomlaupdate/Model/UpdateModel.php#L1302

Yes that should be fixed by an update of the manifest cache (which should add that data). But I'm not sure what this code does at all as it seams to not have an effect as the $extensions is by value and not by ref ;)

not only that module doesn't exists at all (as a core module)
and yes i'm guessing the same, wtf getNonCoreExtensions() means in the com_joomlaupdate

ahh it was introduced by pre update check #17742

If so the same issue should be patched in 3.10 too: https://github.com/joomla/joomla-cms/blob/3.10-dev/administrator/components/com_joomlaupdate/models/default.php#L1379-L1391

maybe even on 3.9

No the pre update check was moved to 3.10

with #21927 no more able to replicate this issue on 4.0

hmm the code still looks unused and would error again when a component don't offer a version tag or is this just me wondering what this code does at all?

is the version tag in a xml manifest mandatory ?

My point is this is code that is not doing anything at all but maybe it is just me. ;)