### 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
push_error(vformat(R"(Expected statement, found "%s" instead.)", previous.get_name()));
				}
			} else {
				end_statement("expression");
			}
			lambda_ended = lambda_ended || has_ended_lambda;
			result = expression;
#ifdef DEBUG_ENABLED
			if (expression != nullptr) {
				switch (expression->type) {
					case Node::CALL:
					case Node::ASSIGNMENT:
					case Node::AWAIT:
					case Node::TERNARY_OPERATOR:
						
						break;
					case Node::LAMBDA:
						
						push_error("Standalone lambdas cannot be accessed. Consider assigning it to a variable.", expression);
						break;
					case Node::LITERAL:
						if (static_cast<GDScriptParser::LiteralNode *>(expression)->value.get_type() == Variant::STRING) {
							
							break;
						}
						[[fallthrough]];
					default:
						push_warning(expression, GDScriptWarning::STANDALONE_EXPRESSION);
				}
			}