### 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
String result;
	int from = 0;
	int buffer_start = 0;
	const int len = line.length();
	bool process = true;
	while (process) {
		switch (r_state) {
			case DOC_LINE_NORMAL: {
				int lb_pos = line.find_char('[', from);
				if (lb_pos < 0) {
					process = false;
					break;
				}
				int rb_pos = line.find_char(']', lb_pos + 1);
				if (rb_pos < 0) {
					process = false;
					break;
				}
				from = rb_pos + 1;
				String tag = line.substr(lb_pos + 1, rb_pos - lb_pos - 1);
				if (tag == "code") {
					r_state = DOC_LINE_IN_CODE;
				} else if (tag == "codeblock") {
					if (lb_pos == 0) {
						line_join = "\n";
					} else {
						result += line.substr(buffer_start, lb_pos - buffer_start) + '\n';
					}
					result += "[codeblock]";
					if (from < len) {