### 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
return members[members_indices[p_name]];
		}
		bool has_member(const StringName &p_name) const {
			return members_indices.has(p_name);
		}
		bool has_function(const StringName &p_name) const {
			return has_member(p_name) && members[members_indices[p_name]].type == Member::FUNCTION;
		}
		template <class T>
		void add_member(T *p_member_node) {
			members_indices[p_member_node->identifier->name] = members.size();
			members.push_back(Member(p_member_node));
		}
		void add_member(const EnumNode::Value &p_enum_value) {
			members_indices[p_enum_value.identifier->name] = members.size();
			members.push_back(Member(p_enum_value));
		}
		void add_member_group(AnnotationNode *p_annotation_node) {
			members_indices[p_annotation_node->export_info.name] = members.size();
			members.push_back(Member(p_annotation_node));
		}
		ClassNode() {
			type = CLASS;
		}
	};
	struct ConstantNode : public AssignableNode {
#ifdef TOOLS_ENABLED
		String doc_description;
#endif 
		ConstantNode() {