### 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
if (p_annotation->name == SNAME("@export_range")) {
		if (export_type.builtin_type == Variant::INT) {
			variable->export_info.type = Variant::INT;
		}
	}
	if (p_annotation->name == SNAME("@export_multiline")) {
		if (export_type.builtin_type == Variant::ARRAY && export_type.has_container_element_type()) {
			DataType inner_type = export_type.get_container_element_type();
			if (inner_type.builtin_type != Variant::STRING) {
				push_error(vformat(R"("%s" annotation on arrays requires a string type but type "%s" was given instead.)", p_annotation->name.operator String(), inner_type.to_string()), variable);
				return false;
			}
			String hint_prefix = itos(inner_type.builtin_type) + "/" + itos(variable->export_info.hint);
			variable->export_info.hint = PROPERTY_HINT_TYPE_STRING;
			variable->export_info.hint_string = hint_prefix + ":" + variable->export_info.hint_string;
			variable->export_info.type = Variant::ARRAY;
			return true;
		} else if (export_type.builtin_type == Variant::DICTIONARY) {
			variable->export_info.type = Variant::DICTIONARY;
			return true;
		} else if (export_type.builtin_type == Variant::PACKED_STRING_ARRAY) {
			String hint_prefix = itos(Variant::STRING) + "/" + itos(variable->export_info.hint);
			variable->export_info.hint = PROPERTY_HINT_TYPE_STRING;
			variable->export_info.hint_string = hint_prefix + ":" + variable->export_info.hint_string;
			variable->export_info.type = Variant::PACKED_STRING_ARRAY;
			return true;
		}
	}
	if (p_annotation->name == SNAME("@export")) {
		if (variable->datatype_specifier == nullptr && variable->initializer == nullptr) {