Fix version constraint

Author: tvdijen

composer.json

@@ -13,7 +13,7 @@
         "php": "^8.2",
         "ext-dom": "*",
 
-        "simplesamlphp/assert": "~1.9.2",
+        "simplesamlphp/assert": "~1.9.1",
         "simplesamlphp/xml-common": "~2.1.2"
     },
     "require-dev": {