Update paragonie/constant_time_encoding

Author: dependabot[bot]

composer.json

@@ -34,7 +34,7 @@
     },
     "require-dev": {
         "httpwg/structured-field-tests": "*@dev",
-        "paragonie/constant_time_encoding": "^2.6.3",
+        "paragonie/constant_time_encoding": "^2.6.3 || ^3.0.0",
         "phpmd/phpmd": "^2.15",
         "phpstan/phpstan": "^1.9",
         "phpstan/phpstan-phpunit": "^1.3",