Fix PHPStan errors; composer update (#147)

Author: tangrufus

composer.lock

@@ -35,9 +35,10 @@ public function __invoke(
 
             $constraint = $composer->requiredPhpConstraint();
 
-            /** @phpstan-ignore method.notFound,return.type */
-            return $application->get('constraint')
-                ->__invoke($io, $constraint, $source, $mode);
+            /** @var ConstraintCommand $constraintCommand */
+            $constraintCommand = $application->get('constraint');
+
+            return $constraintCommand->__invoke($io, $constraint, $source, $mode);
         } catch (ExceptionInterface $e) {
             $this->printError(
                 $io,

src/Console/ComposerCommand.php

@@ -32,6 +32,7 @@ public static function highest(string ...$versions): string
     {
         $sorted = self::sort(...$versions);
 
+        // @phpstan-ignore offsetAccess.invalidOffset
         return $sorted[array_key_last($sorted)];
     }
 }