Bump thruway/client to a php8-compatible version

Author: andrewmy

composer.json

@@ -9,7 +9,7 @@
         "php": "^7.3|^8.0",
         "queue-interop/queue-interop": "^0.8.1",
         "enqueue/dsn": "^0.10.8",
-        "thruway/client": "^0.5",
+        "thruway/client": "^0.5.5",
         "thruway/pawl-transport": "^0.5.1",
         "voryx/thruway-common": "^1.0.1",
         "react/dns": "^1.0",