### 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
is_member = true;
						is_static = false;
						GDScript::MemberInfo &minfo = codegen.script->member_indices[var_name];
						setter_function = minfo.setter;
						has_setter = setter_function != StringName();
						is_in_setter = has_setter && setter_function == codegen.function_name;
						member.mode = GDScriptCodeGenerator::Address::MEMBER;
						member.address = minfo.index;
						member.type = minfo.data_type;
					} else {
						
						GDScript *scr = codegen.script;
						while (scr) {
							if (scr->static_variables_indices.has(var_name)) {
								is_member = true;
								is_static = true;
								GDScript::MemberInfo &minfo = scr->static_variables_indices[var_name];
								setter_function = minfo.setter;
								has_setter = setter_function != StringName();
								is_in_setter = has_setter && setter_function == codegen.function_name;
								static_var_class = codegen.add_constant(scr);
								static_var_index = minfo.index;
								static_var_data_type = minfo.data_type;
								break;
							}
							scr = scr->_base;
						}
					}
				}
				GDScriptCodeGenerator::Address target;