fix: Use clearer error message for credential resolution (#732)

lib/monitoring/monitoring-integration-service.js

@@ -185,9 +185,11 @@ const MonitoringIntegrationService = (serverless) => {
     try {
       return (await stsClient.send(new GetCallerIdentityCommand({}))).Account;
     } catch (error) {
-      throw new Error(
-        'Serverless Framework Observability set-up was unable to determine the Account ID for this AWS account. This likely due to insufficient permissions in the current AWS credentials.'
+      const err = new Error(
+        'AWS provider credentials not found. Learn how to set up AWS provider credentials in our docs here: http://slss.io/aws-creds-setup.'
       );
+      err.stack = undefined;
+      throw err;
     }
   };