I've change the urls variable to be a local, instead of manually allocating it all the time.
This is only used locally and was causing a memory leak because FreeUPNPUrls gave the impression it free it.
1. FreeUPNPUrls doesn't free the pointer passed in, that's up to caller.
2. The second if(!urls) produced dead code as we checked the pointer just after allocation.
We don't use that info for anything, and it generates unnecessary diffs
every time we bump the minor version (and CI failures if we forget to
sync some files from opt-in modules (mono, text_server_fb).
This makes it easier to spot syntax errors when editing the
class reference. The schema is referenced locally so validation
can still work offline.
Each class XML's schema conformance is also checked on GitHub Actions.
For the time being we don't support writing a description for those, preferring
having all details in the method's description.
Using self-closing tags saves half the lines, and prevents contributors from
thinking that they should write the argument or return documentation there.
We already removed it from the online docs with #35132.
Currently it can only be "Built-In Types" (Variant types) or "Core"
(everything else), which is of limited use.
We might also want to consider dropping it from `ClassDB` altogether
in Godot 4.0.
