### 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 codegen.parameters.has(p_name) || codegen.locals.has(p_name);
}
void GDScriptCompiler::_set_error(const String &p_error, const GDScriptParser::Node *p_node) {
	if (!error.is_empty()) {
		return;
	}
	error = p_error;
	if (p_node) {
		err_line = p_node->start_line;
		err_column = p_node->leftmost_column;
	} else {
		err_line = 0;
		err_column = 0;
	}
}
GDScriptDataType GDScriptCompiler::_gdtype_from_datatype(const GDScriptParser::DataType &p_datatype, GDScript *p_owner) {
	if (!p_datatype.is_set() || !p_datatype.is_hard_type() || p_datatype.is_coroutine) {
		return GDScriptDataType();
	}
	GDScriptDataType result;
	result.has_type = true;
	switch (p_datatype.kind) {
		case GDScriptParser::DataType::VARIANT: {
			result.has_type = false;
		} break;
		case GDScriptParser::DataType::BUILTIN: {
			result.kind = GDScriptDataType::BUILTIN;
			result.builtin_type = p_datatype.builtin_type;