Don't abort loading scene on missing dependency

[KoBeWi]

Fixes #54603

Missing error report

[reduz]

It looks good, but don't forget to report the missing resource dependencies via:
ResourceLoader::notify_dependency_error(..)
you can check in the binary format (resource_format_binary.cpp) how this is done.

[KoBeWi]

There is a dependency error already though. It's the same as in binary, but condition order is different.

I misread the code

[reduz]

Its good

[akien-mga]

Thanks!