### 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
gen->write_call_self(temp, codegen.script->member_indices[identifier].getter, args);
						return temp;
					} else {
						
						int idx = codegen.script->member_indices[identifier].index;
						return GDScriptCodeGenerator::Address(GDScriptCodeGenerator::Address::MEMBER, idx, codegen.script->get_member_type(identifier));
					}
				}
			}
			
			{
				GDScript *scr = codegen.script;
				while (scr) {
					if (scr->static_variables_indices.has(identifier)) {
						if (scr->static_variables_indices[identifier].getter != StringName() && scr->static_variables_indices[identifier].getter != codegen.function_name) {
							
							GDScriptCodeGenerator::Address temp = codegen.add_temporary(scr->static_variables_indices[identifier].data_type);
							GDScriptCodeGenerator::Address class_addr(GDScriptCodeGenerator::Address::CLASS);
							Vector<GDScriptCodeGenerator::Address> args; 
							gen->write_call(temp, class_addr, scr->static_variables_indices[identifier].getter, args);
							return temp;
						} else {
							
							GDScriptCodeGenerator::Address temp = codegen.add_temporary(scr->static_variables_indices[identifier].data_type);
							GDScriptCodeGenerator::Address _class = codegen.add_constant(scr);
							int index = scr->static_variables_indices[identifier].index;
							gen->write_get_static_variable(temp, _class, index);
							return temp;
						}
					}