Fix typo

Co-authored-by: JakeQZ <[email protected]>

Author: oliverklee

tests/Unit/CSSList/AtRuleBlockListTest.php

@@ -81,7 +81,7 @@ public function atRuleArgsByDefaultReturnsEmptyString(): void
     /**
      * @test
      */
-    public function atRuleArgusReturnsArgumentsProvidedToConstructor(): void
+    public function atRuleArgsReturnsArgumentsProvidedToConstructor(): void
     {
         $arguments = 'bar';