fix: fix dependency on perun-module

composer.json

@@ -17,7 +17,7 @@
     "require": {
         "simplesamlphp/composer-module-installer": "~1.0",
         "simplesamlphp/simplesamlphp": "~1.17",
-        "cesnet/simplesamlphp-module-perun": "~6.0",
+        "cesnet/simplesamlphp-module-perun": ">=6.0",
         "ext-json": "*",
         "ext-curl": "*"
     },