### 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
assigned = op_result;
				}
				
				if (subscript->is_attribute) {
					gen->write_set_named(prev_base, name, assigned);
				} else {
					gen->write_set(prev_base, key, assigned);
				}
				if (key.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
					gen->pop_temporary();
				}
				if (assigned.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
					gen->pop_temporary();
				}
				assigned = prev_base;
				
				for (const ChainInfo &info : set_chain) {
					bool known_type = assigned.type.has_type;
					bool is_shared = Variant::is_type_shared(assigned.type.builtin_type);
					if (!known_type || !is_shared) {
						if (!known_type) {
							
							gen->write_jump_if_shared(assigned);
						}
						if (!info.is_named) {
							gen->write_set(info.base, info.key, assigned);
						} else {
							gen->write_set_named(info.base, info.name, assigned);
						}
						if (!known_type) {