`worker_extra_flags` not passed through to remote persistent workers

### Description of the bug:

`worker_extra_flag` works locally, but the supplied flags are not passed to the remote worker.

### What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

_No response_

### Which operating system are you running Bazel on?

_No response_

### What is the output of `bazel info release`?

_No response_

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse master; git rev-parse HEAD` ?

_No response_

### Have you found anything relevant by searching the web?

_No response_

### Any other information, logs, or outputs that you want to share?

_No response_

Start by tracing Bazel's remote persistent worker handling for the worker_extra_flags setting and compare it with the local worker path. Reproduce the difference with a minimal remote-worker configuration, then verify that the supplied flags reach the remote worker while local behavior remains unchanged.

Written by the indexing model from the issue text.