Repo failure can cause false credential helper error/warning messages

### Description of the bug:

If a repo rule fails whilst credential helpers are executing, the result is multiple credential helper warnings that can appear both before and after the repo rule error. The result is that the user is diverted to investigating credential helper issues that are not real.

It appears that when bazel aborts credential helper invokations after a repo failure in different thread, warning messages are emitted. These can include:
- credential helper timeout
- credential helper parse error
- attempting to fetch X despite credential helper issue
- failed to fetch X, due to 401 error (because credential helper was stopped)

After an error, threads that are forced to stop should not generate warning or error messages after the force stop.

This happens even with --experimental_worker_for_repo_fetching=off

### Which category does this issue belong to?

External Dependency

### 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?

Windows

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

7.4.0rc2

### 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 HEAD` ?

_No response_

### If this is a regression, please try to identify the Bazel commit where the bug was introduced with bazelisk --bisect.

_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_