Fix new static analysis issue with minimumStability constants

Author: asgrim

.github/workflows/continuous-integration.yml

@@ -18,6 +18,7 @@ jobs:
           - '8.1'
           - '8.2'
           - '8.3'
+          - '8.4'
     steps:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2

composer.lock

@@ -5,14 +5,17 @@
 namespace Php\Pie\DependencyResolver;
 
 use Composer\Composer;
+use Composer\Package\BasePackage;
 use Composer\Package\CompletePackageInterface;
 use Composer\Package\Version\VersionSelector;
 use Composer\Repository\CompositeRepository;
 use Composer\Repository\RepositorySet;
 use Php\Pie\ExtensionType;
 use Php\Pie\Platform\TargetPhp\ResolveTargetPhpToPlatformRepository;
 use Php\Pie\Platform\TargetPlatform;
+use Webmozart\Assert\Assert;
 
+use function array_keys;
 use function preg_match;
 use function str_starts_with;
 
@@ -41,6 +44,9 @@ private function factoryRepositorySet(string|null $requestedVersion): Repository
             }
         }
 
+        Assert::inArray($minimumStability, array_keys(BasePackage::STABILITIES));
+        /** @psalm-var key-of<BasePackage::STABILITIES> $minimumStability */
+
         $repositorySet = new RepositorySet($minimumStability);
         $repositorySet->addRepository(new CompositeRepository($this->composer->getRepositoryManager()->getRepositories()));