### Godot version

v4.0.beta13.official [caacade56]

### System information

Windows 8.1

### Issue description

The `Unreachable code (statement after return) in function 'function_name()'` warning is given for functions that do not have unreachable code. The same code does not give this warning in v3.5.stable.official [991bb6ac7].

### Steps to reproduce

```
func warning(i: int) -> void:
  if i == 0:
    pass
  elif i == 1:
    return
  else:
    return
  print("yeah")
```

Removing either the `elif` or the `else` removes the warning.

### Minimal reproduction project

N/A; code in reproduction steps can be placed in any blank gdscript file to trigger the error.
assignment->operation = AssignmentNode::OP_DIVISION;
			assignment->variant_op = Variant::OP_DIVIDE;
			break;
		case GDScriptTokenizer::Token::PERCENT_EQUAL:
			assignment->operation = AssignmentNode::OP_MODULO;
			assignment->variant_op = Variant::OP_MODULE;
			break;
		case GDScriptTokenizer::Token::LESS_LESS_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_SHIFT_LEFT;
			assignment->variant_op = Variant::OP_SHIFT_LEFT;
			break;
		case GDScriptTokenizer::Token::GREATER_GREATER_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_SHIFT_RIGHT;
			assignment->variant_op = Variant::OP_SHIFT_RIGHT;
			break;
		case GDScriptTokenizer::Token::AMPERSAND_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_AND;
			assignment->variant_op = Variant::OP_BIT_AND;
			break;
		case GDScriptTokenizer::Token::PIPE_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_OR;
			assignment->variant_op = Variant::OP_BIT_OR;
			break;
		case GDScriptTokenizer::Token::CARET_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_XOR;
			assignment->variant_op = Variant::OP_BIT_XOR;
			break;
		default:
			break; 
	}