### Godot version

4.0.beta10

### System information

Windows 11

### Issue description
UPDATE: This problem only occurs when the source code contains inner classes

Before 4.0.Beta9, I could get a GDScript instance by `GDScript.new()` and then set the `source_code` property and then `reload()`, but now it throws an error 
```
USER SCRIPT ERROR: Parse Error: Could not find script "".
   at: GDScript::reload (built-in:1644)
```
In my software, I use the above method when the user modifies the code text, and then read the godot log to implement real-time error checking of the custom user script editor. But now this functionality is completely broken

### Steps to reproduce

1. Create a GDScript instance by `GDScript.new()`
2. set the `source_code` property and then `reload()`

### Minimal reproduction project

N/A
for (const KeyValue<String, DocData::EnumDoc> &E : doc_enums) {
		if (!E.value.description.is_empty()) {
			doc.enums[E.key] = E.value.description;
		}
	}
	List<MethodInfo> methods;
	_get_script_method_list(&methods, false);
	for (int i = 0; i < methods.size(); i++) {
		
		if (methods[i].name[0] == '@') {
			continue;
		}
		DocData::MethodDoc method_doc;
		const String &class_name = methods[i].name;
		if (member_functions.has(class_name)) {
			GDScriptFunction *fn = member_functions[class_name];
			
			GDScriptDataType return_type = fn->get_return_type();
			if (return_type.kind == GDScriptDataType::GDSCRIPT) {
				methods[i].return_val.class_name = _get_gdscript_reference_class_name(Object::cast_to<GDScript>(return_type.script_type));
			}
			
			for (int j = 0; j < fn->get_argument_count(); j++) {
				GDScriptDataType arg_type = fn->get_argument_type(j);
				if (arg_type.kind == GDScriptDataType::GDSCRIPT) {
					methods[i].arguments[j].class_name = _get_gdscript_reference_class_name(Object::cast_to<GDScript>(arg_type.script_type));
				}
			}
		}
		if (doc_functions.has(methods[i].name)) {