### Godot version

4.1.1

### System information

windows 11

### Issue description

When registering a type with class_name and using that class name to declare a variable in code only, autocomplete works as expected anywhere in other nodes/scenes. However, if making a custom scene node that extends a script with the class_name, if that custom scene is instantiated in a different scene, even if the type is specified, it only shows the parent node's functions and not any of the extended functionality. I have made a basic project showing the issue

### Steps to reproduce

I have made a very simple project showing the issue. https://github.com/mmmmmmmmmmmmmmmmmmmdonuts/godot_4_autocomplete_issue essentially, the extended Node scene will only show the custom function when both the type is specified as well as the type afterwards following "as" 
e.g. `@onready var my_class_4: MyClass = $MyClass4 as MyClass`

### Minimal reproduction project

https://github.com/mmmmmmmmmmmmmmmmmmmdonuts/godot_4_autocomplete_issue
}
						option = ScriptLanguage::CodeCompletionOption(member.constant->identifier->name, ScriptLanguage::CODE_COMPLETION_KIND_CONSTANT, location);
						if (member.constant->initializer) {
							option.default_value = member.constant->initializer->reduced_value;
						}
						break;
					case GDScriptParser::ClassNode::Member::CLASS:
						if (p_only_functions) {
							continue;
						}
						option = ScriptLanguage::CodeCompletionOption(member.m_class->identifier->name, ScriptLanguage::CODE_COMPLETION_KIND_CLASS, location);
						break;
					case GDScriptParser::ClassNode::Member::ENUM_VALUE:
						if (p_only_functions) {
							continue;
						}
						option = ScriptLanguage::CodeCompletionOption(member.enum_value.identifier->name, ScriptLanguage::CODE_COMPLETION_KIND_CONSTANT, location);
						break;
					case GDScriptParser::ClassNode::Member::ENUM:
						if (p_only_functions) {
							continue;
						}
						option = ScriptLanguage::CodeCompletionOption(member.m_enum->identifier->name, ScriptLanguage::CODE_COMPLETION_KIND_ENUM, location);
						break;
					case GDScriptParser::ClassNode::Member::FUNCTION:
						if (outer || (p_static && !member.function->is_static) || member.function->identifier->name.operator String().begins_with("@")) {
							continue;
						}
						option = ScriptLanguage::CodeCompletionOption(member.function->identifier->name, ScriptLanguage::CODE_COMPLETION_KIND_FUNCTION, location);
						if (member.function->parameters.size() > 0) {