[4.1][Static Analysis] Using PhpVersion::PHP_73 constant in rector ^0.9

Author: samsonasik

rector.php

@@ -1,6 +1,7 @@
 <?php
 
 use Rector\Core\Configuration\Option;
+use Rector\Core\ValueObject\PhpVersion;
 use Rector\CodeQuality\Rector\Return_\SimplifyUselessVariableRector;
 use Rector\Performance\Rector\FuncCall\CountArrayToEmptyArrayComparisonRector;
 use Rector\SOLID\Rector\If_\RemoveAlwaysElseRector;
@@ -30,7 +31,7 @@
 	// auto import fully qualified class names
 	$parameters->set(Option::AUTO_IMPORT_NAMES, true);
 	$parameters->set(Option::ENABLE_CACHE, true);
-	$parameters->set(Option::PHP_VERSION_FEATURES, '7.3');
+	$parameters->set(Option::PHP_VERSION_FEATURES, PhpVersion::PHP_73);
 
 	$services = $containerConfigurator->services();
 	$services->set(UnderscoreToCamelCaseVariableNameRector::class);