### 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
GDScriptDataType static_var_data_type;
				StringName var_name;
				StringName member_property_setter_function;
				List<const GDScriptParser::SubscriptNode *> chain;
				{
					
					const GDScriptParser::SubscriptNode *n = subscript;
					while (true) {
						chain.push_back(n);
						if (n->base->type != GDScriptParser::Node::SUBSCRIPT) {
							
							if (n->base->type == GDScriptParser::Node::IDENTIFIER) {
								GDScriptParser::IdentifierNode *identifier = static_cast<GDScriptParser::IdentifierNode *>(n->base);
								var_name = identifier->name;
								if (_is_class_member_property(codegen, var_name)) {
									assign_class_member_property = var_name;
								} else if (!_is_local_or_parameter(codegen, var_name)) {
									if (codegen.script->member_indices.has(var_name)) {
										is_member_property = true;
										is_static = false;
										const GDScript::MemberInfo &minfo = codegen.script->member_indices[var_name];
										member_property_setter_function = minfo.setter;
										member_property_has_setter = member_property_setter_function != StringName();
										member_property_is_in_setter = member_property_has_setter && member_property_setter_function == codegen.function_name;
										target_member_property.mode = GDScriptCodeGenerator::Address::MEMBER;
										target_member_property.address = minfo.index;
										target_member_property.type = minfo.data_type;
									} else {
										
										GDScript *scr = codegen.script;