### Godot version

v4.0.3.stable.official [5222a99f5]
Master [6101240231600c871f5c5473872532c68ea3268c] (confirmed by https://github.com/godotengine/godot/issues/77666#issuecomment-1568952502)

### System information

Window 10

### Issue description

References are not unreferenced at the end of `if` scopes.

### Steps to reproduce

Copy, paste and run the snippet below, check the results:

```gdscript
extends Node


func _ready() -> void:
  var ref := RefCounted.new()
  var ref_count : int

  # OK
  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)

  # OK
  if true:
    var temp := ref
    temp = null

  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)

  # FAIL
  if true:
    var temp := ref

  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)
```

Output example:

```
Expected: 1, Result: 1
Expected: 1, Result: 1
Expected: 1, Result: 2
```

### Minimal reproduction project

N/A
} else if (head->has_member(first)) {
		class_names = p_qualified_name.split("::");
		GDScriptParser::ClassNode::Member member = head->get_member(first);
		if (member.type == GDScriptParser::ClassNode::Member::CLASS) {
			result = member.m_class;
		}
	}
	
	for (int i = 1; result != nullptr && i < class_names.size(); i++) {
		String current_name = class_names[i];
		GDScriptParser::ClassNode *next = nullptr;
		if (result->has_member(current_name)) {
			GDScriptParser::ClassNode::Member member = result->get_member(current_name);
			if (member.type == GDScriptParser::ClassNode::Member::CLASS) {
				next = member.m_class;
			}
		}
		result = next;
	}
	return result;
}
bool GDScriptParser::has_class(const GDScriptParser::ClassNode *p_class) const {
	if (head->fqcn.is_empty() && p_class->fqcn.get_slice("::", 0).is_empty()) {
		return p_class == head;
	} else if (p_class->fqcn.begins_with(head->fqcn)) {
		return find_class(p_class->fqcn.trim_prefix(head->fqcn)) == p_class;
	}
	return false;
}
GDScriptParser::ClassNode *GDScriptParser::parse_class(bool p_is_static) {