RuleInclusionTest: work round removal of assertObjectHasAttribute()

The `assertObjectHasAttribute()` method was deprecated in PHPUnit 9.6.x and removed in PHPUnit 10.0.0 without replacement.
Note: PHPUnit 10.1.0 adds the assertion back again, but under a different name `assertObjectHasProperty()`.

While only a deprecation warning is shown on PHPUnit 9.6.x and the tests will still pass, I'm electing to replace the assertion anyway with code which emulates what PHPUnit would assert.

Author: jrfnl

tests/Core/Ruleset/RuleInclusionTest.php

@@ -12,6 +12,7 @@
 use PHP_CodeSniffer\Config;
 use PHP_CodeSniffer\Ruleset;
 use PHPUnit\Framework\TestCase;
+use ReflectionObject;
 
 class RuleInclusionTest extends TestCase
 {
@@ -222,7 +223,10 @@ public function dataRegisteredSniffCodes()
     public function testSettingProperties($sniffClass, $propertyName, $expectedValue)
     {
         $this->assertArrayHasKey($sniffClass, self::$ruleset->sniffs);
-        $this->assertObjectHasAttribute($propertyName, self::$ruleset->sniffs[$sniffClass]);
+
+        $hasProperty = (new ReflectionObject(self::$ruleset->sniffs[$sniffClass]))->hasProperty($propertyName);
+        $errorMsg    = sprintf('Property %s does not exist on sniff class %s', $propertyName, $sniffClass);
+        $this->assertTrue($hasProperty, $errorMsg);
 
         $actualValue = self::$ruleset->sniffs[$sniffClass]->$propertyName;
         $this->assertSame($expectedValue, $actualValue);