Deduplicate RuleErrorBuilder call in EnumCaseOutsideEnumRule

Restructure the condition logic to return early for the valid case
(enum context) and have a single RuleErrorBuilder call for all
invalid contexts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

src/Rules/EnumCases/EnumCaseOutsideEnumRule.php

@@ -22,21 +22,7 @@ public function getNodeType(): string
 
 	public function processNode(Node $node, Scope $scope): array
 	{
-		if ($scope->isInTrait()) {
-			return [
-				RuleErrorBuilder::message('Enum case can only be used in enums.')
-					->nonIgnorable()
-					->identifier('enum.caseOutsideOfEnum')
-					->build(),
-			];
-		}
-
-		if (!$scope->isInClass()) {
-			return [];
-		}
-
-		$classReflection = $scope->getClassReflection();
-		if ($classReflection->isEnum()) {
+		if (!$scope->isInTrait() && $scope->isInClass() && $scope->getClassReflection()->isEnum()) {
 			return [];
 		}