### 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
public:
	
	struct AnnotationNode;
	struct ArrayNode;
	struct AssertNode;
	struct AssignableNode;
	struct AssignmentNode;
	struct AwaitNode;
	struct BinaryOpNode;
	struct BreakNode;
	struct BreakpointNode;
	struct CallNode;
	struct CastNode;
	struct ClassNode;
	struct ConstantNode;
	struct ContinueNode;
	struct DictionaryNode;
	struct EnumNode;
	struct ExpressionNode;
	struct ForNode;
	struct FunctionNode;
	struct GetNodeNode;
	struct IdentifierNode;
	struct IfNode;
	struct LambdaNode;
	struct LiteralNode;
	struct MatchNode;
	struct MatchBranchNode;
	struct ParameterNode;
	struct PassNode;