Fix use after free in GDScriptLanguage::debug_get_globals

[0x0ACB]

The Object* cast operator of Variant does not validate that the object still exists. This means that in the case you eg queue_free an autoload class this will crash on the next script error due to trying to dynamic_cast a freed pointer.

Not sure get_validated_object_with_check is needed or if get_validated_object would have been enough. But I think better safe than sorry in this case.

There would also be the option of printing a warning/error here since I don't think you should really free autoloads intentionally.

• Bugsquad edit: Fixes Freed autoload object causes debugger to crash without a meaningful error message (GDScript) #92607.

[vnen]

LGTM

[akien-mga]

Thanks!