[CLEANUP] Use RuleSet::removeMatchingRules() in tests (#1254)

Now this method has been added, using it appropriately in the tests,
rather than the deprecated functionality, will eliminate a PHPStan warning.

Note that PHPStan seems to erroneously place the warning against the callee
rather than the caller.

Author: JakeQZ

config/phpstan-baseline.neon

@@ -54,12 +54,6 @@ parameters:
 			count: 1
 			path: ../src/RuleSet/DeclarationBlock.php
 
-		-
-			message: '#^Parameters should have "string" types as the only types passed to this method$#'
-			identifier: typePerfect.narrowPublicClassMethodParamType
-			count: 1
-			path: ../src/RuleSet/RuleSet.php
-
 		-
 			message: '#^Loose comparison via "\!\=" is not allowed\.$#'
 			identifier: notEqual.notAllowed

tests/ParserTest.php

@@ -348,7 +348,7 @@ public function manipulation(): void
             $document->render()
         );
         foreach ($document->getAllRuleSets() as $ruleSet) {
-            $ruleSet->removeRule('font-');
+            $ruleSet->removeMatchingRules('font-');
         }
         self::assertSame(
             '#header {margin: 10px 2em 1cm 2%;color: red !important;background-color: green;'
@@ -357,7 +357,7 @@ public function manipulation(): void
             $document->render()
         );
         foreach ($document->getAllRuleSets() as $ruleSet) {
-            $ruleSet->removeRule('background-');
+            $ruleSet->removeMatchingRules('background-');
         }
         self::assertSame(
             '#header {margin: 10px 2em 1cm 2%;color: red !important;frequency: 30Hz;transform: rotate(1turn);}