### 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
COMPLETION_OVERRIDE_METHOD, 
		COMPLETION_PROPERTY_DECLARATION, 
		COMPLETION_PROPERTY_DECLARATION_OR_TYPE, 
		COMPLETION_PROPERTY_METHOD, 
		COMPLETION_RESOURCE_PATH, 
		COMPLETION_SUBSCRIPT, 
		COMPLETION_SUPER_METHOD, 
		COMPLETION_TYPE_ATTRIBUTE, 
		COMPLETION_TYPE_NAME, 
		COMPLETION_TYPE_NAME_OR_VOID, 
	};
	struct CompletionContext {
		CompletionType type = COMPLETION_NONE;
		ClassNode *current_class = nullptr;
		FunctionNode *current_function = nullptr;
		SuiteNode *current_suite = nullptr;
		int current_line = -1;
		int current_argument = -1;
		Variant::Type builtin_type = Variant::VARIANT_MAX;
		Node *node = nullptr;
		Object *base = nullptr;
		List<Ref<GDScriptParserRef>> dependent_parsers;
	};
	struct CompletionCall {
		Node *call = nullptr;
		int argument = -1;
	};
private:
	friend class GDScriptAnalyzer;
	bool _is_tool = false;