### 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
#include "gdscript_compiler.h"
#include "gdscript.h"
#include "gdscript_byte_codegen.h"
#include "gdscript_cache.h"
#include "gdscript_utility_functions.h"
#include "core/config/engine.h"
#include "core/config/project_settings.h"
bool GDScriptCompiler::_is_class_member_property(CodeGen &codegen, const StringName &p_name) {
	if (codegen.function_node && codegen.function_node->is_static) {
		return false;
	}
	if (_is_local_or_parameter(codegen, p_name)) {
		return false; 
	}
	return _is_class_member_property(codegen.script, p_name);
}
bool GDScriptCompiler::_is_class_member_property(GDScript *owner, const StringName &p_name) {
	GDScript *scr = owner;
	GDScriptNativeClass *nc = nullptr;
	while (scr) {
		if (scr->native.is_valid()) {
			nc = scr->native.ptr();
		}
		scr = scr->_base;
	}
	ERR_FAIL_COND_V(!nc, false);
	return ClassDB::has_property(nc->get_name(), p_name);
}
bool GDScriptCompiler::_is_local_or_parameter(CodeGen &codegen, const StringName &p_name) {