fix(webapp): disable the webhook worker when workers are turned off

WEBHOOK_WORKER_ENABLED defaults from WORKER_ENABLED and follows the same
true/false convention as the other worker switches, but the engine compared it
to "0" (the convention of a different set of flags). A web-only instance
(WORKER_ENABLED=false) therefore kept running webhook delivery jobs once the
feature was enabled. Compare against "true" like its peers.

Author: ericallam

apps/webapp/app/v3/webhookEngine.server.ts

@@ -56,7 +56,7 @@ function createWebhookEngine() {
       tasksPerWorker: env.WEBHOOK_WORKER_CONCURRENCY_TASKS_PER_WORKER,
       pollIntervalMs: env.WEBHOOK_WORKER_POLL_INTERVAL,
       shutdownTimeoutMs: env.WEBHOOK_WORKER_SHUTDOWN_TIMEOUT_MS,
-      disabled: env.WEBHOOK_ENABLED !== "1" || env.WEBHOOK_WORKER_ENABLED === "0",
+      disabled: env.WEBHOOK_ENABLED !== "1" || env.WEBHOOK_WORKER_ENABLED !== "true",
     },
     partitions: {
       ensureSchedule: env.WEBHOOK_PARTITION_ENSURE_SCHEDULE,