Trim quotes from frankenphp app path to ensure valid directory check

src/Package/Target/php/frankenphp.php

@@ -140,6 +140,7 @@ trait frankenphp
         $frankenphpAppPath = $package->getBuildOption('with-frankenphp-app');
 
         if ($frankenphpAppPath) {
+            $frankenphpAppPath = trim($frankenphpAppPath, "\"'");
             if (!is_dir($frankenphpAppPath)) {
                 throw new WrongUsageException("The path provided to --with-frankenphp-app is not a valid directory: {$frankenphpAppPath}");
             }