### 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
case GDScriptParser::DictionaryNode::LUA_TABLE:
						
						StringName key = dn->elements[i].key->reduced_value.operator StringName();
						element = codegen.add_constant(key);
						break;
				}
				elements.push_back(element);
				element = _parse_expression(codegen, r_error, dn->elements[i].value);
				if (r_error) {
					return GDScriptCodeGenerator::Address();
				}
				elements.push_back(element);
			}
			gen->write_construct_dictionary(result, elements);
			for (int i = 0; i < elements.size(); i++) {
				if (elements[i].mode == GDScriptCodeGenerator::Address::TEMPORARY) {
					gen->pop_temporary();
				}
			}
			return result;
		} break;
		case GDScriptParser::Node::CAST: {
			const GDScriptParser::CastNode *cn = static_cast<const GDScriptParser::CastNode *>(p_expression);
			GDScriptDataType cast_type = _gdtype_from_datatype(cn->get_datatype(), codegen.script);
			GDScriptCodeGenerator::Address result;
			if (cast_type.has_type) {
				
				result = codegen.add_temporary(cast_type);
				GDScriptCodeGenerator::Address src = _parse_expression(codegen, r_error, cn->operand);
				gen->write_cast(result, src, cast_type);