RuleInclusion*Test: remove a few redundant assertions

These assertions are checking whether explicitly declared properties exist, which is redundant.

Removing the assertions does not diminish the value of the tests as there are follow-up assertions testing the value of the properties.

Removing the assertions also gets rid of a warning thrown in PHPUnit 9.6.x about the `assertObjectHasAttribute()` assertion being removed in PHPUnit 10.0.
Note: PHPUnit 10.1.0 adds these assertions back again, but under a different name `assertObjectHasProperty()`.

Author: jrfnl

tests/Core/Ruleset/RuleInclusionAbsoluteLinuxTest.php

@@ -98,7 +98,6 @@ public function tearDown()
     public function testLinuxStylePathRuleInclusion()
     {
         // Test that the sniff is correctly registered.
-        $this->assertObjectHasAttribute('sniffCodes', $this->ruleset);
         $this->assertCount(1, $this->ruleset->sniffCodes);
         $this->assertArrayHasKey('Generic.Formatting.SpaceAfterNot', $this->ruleset->sniffCodes);
         $this->assertSame(

tests/Core/Ruleset/RuleInclusionAbsoluteWindowsTest.php

@@ -99,7 +99,6 @@ public function tearDown()
     public function testWindowsStylePathRuleInclusion()
     {
         // Test that the sniff is correctly registered.
-        $this->assertObjectHasAttribute('sniffCodes', $this->ruleset);
         $this->assertCount(1, $this->ruleset->sniffCodes);
         $this->assertArrayHasKey('Generic.Formatting.SpaceAfterCast', $this->ruleset->sniffCodes);
         $this->assertSame(

tests/Core/Ruleset/RuleInclusionTest.php

@@ -113,7 +113,6 @@ public function tearDown()
      */
     public function testHasSniffCodes()
     {
-        $this->assertObjectHasAttribute('sniffCodes', self::$ruleset);
         $this->assertCount(14, self::$ruleset->sniffCodes);
 
     }//end testHasSniffCodes()
@@ -222,7 +221,6 @@ public function dataRegisteredSniffCodes()
      */
     public function testSettingProperties($sniffClass, $propertyName, $expectedValue)
     {
-        $this->assertObjectHasAttribute('sniffs', self::$ruleset);
         $this->assertArrayHasKey($sniffClass, self::$ruleset->sniffs);
         $this->assertObjectHasAttribute($propertyName, self::$ruleset->sniffs[$sniffClass]);