fix(cloudflare): preserve dev worker registration on reload

[utopyin]

hi! I'm getting Worker "home-api-dev-utopy-ijmmtvj5spgzktlm" not found. Make sure the worker is running locally in the rpc response whenever the backend code of my Api worker changes. It looks like a race condition.

Here's what the agent thinks is happpening:

1. API hot reload starts and registers the replacement worker.
2. Alchemy then asynchronously closes the previous worker scope in LocalWorkerProvider.ts:221-225.
3. The old scope finalizer deletes the registry file by worker name in Registry.ts:124-136.
4. Because both versions share the same name, it deletes the new worker’s registration.
5. The web worker’s service binding can no longer resolve the API and returns the reported 503.

This seems to have fixed it on my end, not sure if this is not a regression though