### 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
Local(ConstantNode *p_constant, FunctionNode *p_source_function) {
				type = CONSTANT;
				constant = p_constant;
				name = p_constant->identifier->name;
				source_function = p_source_function;
				start_line = p_constant->start_line;
				end_line = p_constant->end_line;
				start_column = p_constant->start_column;
				end_column = p_constant->end_column;
				leftmost_column = p_constant->leftmost_column;
				rightmost_column = p_constant->rightmost_column;
			}
			Local(VariableNode *p_variable, FunctionNode *p_source_function) {