### 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 err = OK;
	GDScriptCodeGenerator *gen = codegen.generator;
	gen->clean_temporaries();
	codegen.start_block();
	if (p_add_locals) {
		_add_locals_in_block(codegen, p_block);
	}
	for (int i = 0; i < p_block->statements.size(); i++) {
		const GDScriptParser::Node *s = p_block->statements[i];
#ifdef DEBUG_ENABLED
		
		gen->write_newline(s->start_line);
#endif
		switch (s->type) {
			case GDScriptParser::Node::MATCH: {
				const GDScriptParser::MatchNode *match = static_cast<const GDScriptParser::MatchNode *>(s);
				codegen.start_block();
				
				GDScriptCodeGenerator::Address value = codegen.add_local("@match_value", _gdtype_from_datatype(match->test->get_datatype(), codegen.script));
				GDScriptCodeGenerator::Address value_expr = _parse_expression(codegen, err, match->test);
				if (err) {
					return err;
				}
				
				
				gen->write_assign(value, value_expr);
				if (value_expr.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
					codegen.generator->pop_temporary();