### 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
scr = scr->_base;
				}
			}
			
			{
				GDScript *owner = codegen.script;
				while (owner) {
					GDScript *scr = owner;
					GDScriptNativeClass *nc = nullptr;
					while (scr) {
						if (scr->constants.has(identifier)) {
							return codegen.add_constant(scr->constants[identifier]); 
						}
						if (scr->native.is_valid()) {
							nc = scr->native.ptr();
						}
						scr = scr->_base;
					}
					
					if (nc) {
						bool success = false;
						int64_t constant = ClassDB::get_integer_constant(nc->get_name(), identifier, &success);
						if (success) {
							return codegen.add_constant(constant);
						}
					}
					owner = owner->_owner;
				}
			}