### 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
Error _create_binary_operator(CodeGen &codegen, const GDScriptParser::BinaryOpNode *on, Variant::Operator op, bool p_initializer = false, const GDScriptCodeGenerator::Address &p_index_addr = GDScriptCodeGenerator::Address());
	Error _create_binary_operator(CodeGen &codegen, const GDScriptParser::ExpressionNode *p_left_operand, const GDScriptParser::ExpressionNode *p_right_operand, Variant::Operator op, bool p_initializer = false, const GDScriptCodeGenerator::Address &p_index_addr = GDScriptCodeGenerator::Address());
	GDScriptDataType _gdtype_from_datatype(const GDScriptParser::DataType &p_datatype, GDScript *p_owner);
	GDScriptCodeGenerator::Address _parse_assign_right_expression(CodeGen &codegen, Error &r_error, const GDScriptParser::AssignmentNode *p_assignmentint, const GDScriptCodeGenerator::Address &p_index_addr = GDScriptCodeGenerator::Address());
	GDScriptCodeGenerator::Address _parse_expression(CodeGen &codegen, Error &r_error, const GDScriptParser::ExpressionNode *p_expression, bool p_root = false, bool p_initializer = false, const GDScriptCodeGenerator::Address &p_index_addr = GDScriptCodeGenerator::Address());
	GDScriptCodeGenerator::Address _parse_match_pattern(CodeGen &codegen, Error &r_error, const GDScriptParser::PatternNode *p_pattern, const GDScriptCodeGenerator::Address &p_value_addr, const GDScriptCodeGenerator::Address &p_type_addr, const GDScriptCodeGenerator::Address &p_previous_test, bool p_is_first, bool p_is_nested);
	void _add_locals_in_block(CodeGen &codegen, const GDScriptParser::SuiteNode *p_block);
	Error _parse_block(CodeGen &codegen, const GDScriptParser::SuiteNode *p_block, bool p_add_locals = true);
	GDScriptFunction *_parse_function(Error &r_error, GDScript *p_script, const GDScriptParser::ClassNode *p_class, const GDScriptParser::FunctionNode *p_func, bool p_for_ready = false, bool p_for_lambda = false);
	GDScriptFunction *_make_static_initializer(Error &r_error, GDScript *p_script, const GDScriptParser::ClassNode *p_class);
	Error _parse_setter_getter(GDScript *p_script, const GDScriptParser::ClassNode *p_class, const GDScriptParser::VariableNode *p_variable, bool p_is_setter);
	Error _populate_class_members(GDScript *p_script, const GDScriptParser::ClassNode *p_class, bool p_keep_state);
	Error _compile_class(GDScript *p_script, const GDScriptParser::ClassNode *p_class, bool p_keep_state);
	int err_line = 0;
	int err_column = 0;
	StringName source;
	String error;
	GDScriptParser::ExpressionNode *awaited_node = nullptr;
	bool has_static_data = false;
public:
	static void convert_to_initializer_type(Variant &p_variant, const GDScriptParser::VariableNode *p_node);
	static void make_scripts(GDScript *p_script, const GDScriptParser::ClassNode *p_class, bool p_keep_state);
	Error compile(const GDScriptParser *p_parser, GDScript *p_script, bool p_keep_state = false);
	String get_error() const;
	int get_error_line() const;
	int get_error_column() const;
	GDScriptCompiler();
};
#endif