### 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
return temp;
				}
			}
			
			if (GDScriptLanguage::get_singleton()->get_global_map().has(identifier)) {
				
				
				HashMap<StringName, ProjectSettings::AutoloadInfo> autoloads = ProjectSettings::get_singleton()->get_autoload_list();
				if (autoloads.has(identifier) && autoloads[identifier].is_singleton) {
					GDScriptCodeGenerator::Address global = codegen.add_temporary(_gdtype_from_datatype(in->get_datatype(), codegen.script));
					int idx = GDScriptLanguage::get_singleton()->get_global_map()[identifier];
					gen->write_store_global(global, idx);
					return global;
				} else {
					int idx = GDScriptLanguage::get_singleton()->get_global_map()[identifier];
					Variant global = GDScriptLanguage::get_singleton()->get_global_array()[idx];
					return codegen.add_constant(global);
				}
			}
			
			if (ScriptServer::is_global_class(identifier)) {
				const GDScriptParser::ClassNode *class_node = codegen.class_node;
				while (class_node->outer) {
					class_node = class_node->outer;
				}
				Ref<Resource> res;
				if (class_node->identifier && class_node->identifier->name == identifier) {
					res = Ref<GDScript>(main_script);
				} else {
					String global_class_path = ScriptServer::get_global_class_path(identifier);