Cloudflare instrument dispatcher

### Problem Statement

Docs: https://developers.cloudflare.com/cloudflare-for-platforms/workers-for-platforms/get-started/

When using a dispatcher probably no tracing is enabled.

### Solution Brainstorm

Best would be to only allow trace propagation and instrument the `Fetcher` which gets returned by the fetcher (https://github.com/getsentry/sentry-javascript/blob/53c98be7f3b1df49806210eaa5c2750cd2d2b6f9/packages/cloudflare/src/instrumentations/worker/instrumentFetcher.ts)

### Additional Context

_No response_

### Priority

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