### 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 equality_type;
			equality_type.has_type = true;
			equality_type.kind = GDScriptDataType::BUILTIN;
			equality_type.builtin_type = Variant::BOOL;
			
			GDScriptCodeGenerator::Address type_equality_addr = codegen.add_temporary(equality_type);
			codegen.generator->write_binary_operator(type_equality_addr, Variant::OP_EQUAL, p_type_addr, literal_type_addr);
			if (literal_type == Variant::STRING) {
				GDScriptCodeGenerator::Address type_stringname_addr = codegen.add_constant(Variant::STRING_NAME);
				
				GDScriptCodeGenerator::Address tmp_comp_addr = codegen.add_temporary(equality_type);
				codegen.generator->write_binary_operator(tmp_comp_addr, Variant::OP_EQUAL, p_type_addr, type_stringname_addr);
				codegen.generator->write_binary_operator(type_equality_addr, Variant::OP_OR, type_equality_addr, tmp_comp_addr);
				codegen.generator->pop_temporary(); 
			} else if (literal_type == Variant::STRING_NAME) {
				GDScriptCodeGenerator::Address type_string_addr = codegen.add_constant(Variant::STRING);
				
				GDScriptCodeGenerator::Address tmp_comp_addr = codegen.add_temporary(equality_type);
				codegen.generator->write_binary_operator(tmp_comp_addr, Variant::OP_EQUAL, p_type_addr, type_string_addr);
				codegen.generator->write_binary_operator(type_equality_addr, Variant::OP_OR, type_equality_addr, tmp_comp_addr);
				codegen.generator->pop_temporary(); 
			}
			codegen.generator->write_and_left_operand(type_equality_addr);
			
			GDScriptCodeGenerator::Address literal_addr = _parse_expression(codegen, r_error, p_pattern->literal);
			if (r_error) {
				return GDScriptCodeGenerator::Address();
			}
			
			GDScriptCodeGenerator::Address equality_addr = codegen.add_temporary(equality_type);