test: pin verified rivetkit preview

Author: NathanFlurry

packages/workflows/package.json

@@ -72,7 +72,7 @@
 		"commander": "^12.0.0",
 		"legacy-rivetkit": "npm:rivetkit@2.3.7",
 		"legacy-workflow-engine": "npm:@rivetkit/workflow-engine@2.3.7",
-		"rivetkit": "0.0.0-feat-workflows-public-host-apis.0ff6164",
+		"rivetkit": "0.0.0-feat-workflows-public-host-apis.1550fe4",
 		"tsup": "^8.4.0",
 		"tsx": "^4.7.0",
 		"typescript": "^5.7.3",