Update dependencies (#35)

Author: dfridrich

composer.json

@@ -13,11 +13,11 @@
     ],
     "require": {
         "php": "^7.4|^8.0",
-        "beberlei/assert": "^2.4",
+        "beberlei/assert": "^2.4|^3.0",
         "dfridrich/library": "^1.37.14",
         "ext-simplexml": "*",
         "fabpot/goutte": "^4.0",
-        "symfony/string": "^5|^6"
+        "symfony/string": "^4|^5|^6"
     },
     "require-dev": {
         "symplify/coding-standard": "^8",