### 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
register_annotation(MethodInfo("@export_dir"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_DIR, Variant::STRING>);
	register_annotation(MethodInfo("@export_global_file", PropertyInfo(Variant::STRING, "filter")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_GLOBAL_FILE, Variant::STRING>, varray(""), true);
	register_annotation(MethodInfo("@export_global_dir"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_GLOBAL_DIR, Variant::STRING>);
	register_annotation(MethodInfo("@export_multiline"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_MULTILINE_TEXT, Variant::STRING>);
	register_annotation(MethodInfo("@export_placeholder", PropertyInfo(Variant::STRING, "placeholder")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_PLACEHOLDER_TEXT, Variant::STRING>);
	register_annotation(MethodInfo("@export_range", PropertyInfo(Variant::FLOAT, "min"), PropertyInfo(Variant::FLOAT, "max"), PropertyInfo(Variant::FLOAT, "step"), PropertyInfo(Variant::STRING, "extra_hints")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_RANGE, Variant::FLOAT>, varray(1.0, ""), true);
	register_annotation(MethodInfo("@export_exp_easing", PropertyInfo(Variant::STRING, "hints")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_EXP_EASING, Variant::FLOAT>, varray(""), true);
	register_annotation(MethodInfo("@export_color_no_alpha"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_COLOR_NO_ALPHA, Variant::COLOR>);
	register_annotation(MethodInfo("@export_node_path", PropertyInfo(Variant::STRING, "type")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_NODE_PATH_VALID_TYPES, Variant::NODE_PATH>, varray(""), true);
	register_annotation(MethodInfo("@export_flags", PropertyInfo(Variant::STRING, "names")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_FLAGS, Variant::INT>, varray(), true);
	register_annotation(MethodInfo("@export_flags_2d_render"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_2D_RENDER, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_2d_physics"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_2D_PHYSICS, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_2d_navigation"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_2D_NAVIGATION, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_3d_render"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_3D_RENDER, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_3d_physics"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_3D_PHYSICS, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_3d_navigation"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_3D_NAVIGATION, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_avoidance"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_AVOIDANCE, Variant::INT>);
	
	register_annotation(MethodInfo("@export_category", PropertyInfo(Variant::STRING, "name")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_CATEGORY>);
	register_annotation(MethodInfo("@export_group", PropertyInfo(Variant::STRING, "name"), PropertyInfo(Variant::STRING, "prefix")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_GROUP>, varray(""));
	register_annotation(MethodInfo("@export_subgroup", PropertyInfo(Variant::STRING, "name"), PropertyInfo(Variant::STRING, "prefix")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_SUBGROUP>, varray(""));
	
	register_annotation(MethodInfo("@warning_ignore", PropertyInfo(Variant::STRING, "warning")), AnnotationInfo::CLASS | AnnotationInfo::VARIABLE | AnnotationInfo::SIGNAL | AnnotationInfo::CONSTANT | AnnotationInfo::FUNCTION | AnnotationInfo::STATEMENT, &GDScriptParser::warning_annotations, varray(), true);
	
	register_annotation(MethodInfo("@rpc", PropertyInfo(Variant::STRING, "mode"), PropertyInfo(Variant::STRING, "sync"), PropertyInfo(Variant::STRING, "transfer_mode"), PropertyInfo(Variant::INT, "transfer_channel")), AnnotationInfo::FUNCTION, &GDScriptParser::rpc_annotation, varray("authority", "call_remote", "unreliable", 0));
#ifdef DEBUG_ENABLED
	is_ignoring_warnings = !(bool)GLOBAL_GET("debug/gdscript/warnings/enable");
#endif
}
GDScriptParser::~GDScriptParser() {