Unable to write all BEP events to file due to 'java.io.IOException: No available uploader' with experimental_stream_log_file_uploads=true

### Description of the bug:

Bazel crashes when trying to write BEP events to file (`--build_event_binary_file` or `--build_event_text_file`) with `experimental_stream_log_file_uploads` option enabled:

`ERROR: Unable to write all BEP events to file due to 'java.io.IOException: No available uploader'`

### Which category does this issue belong to?

Core

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

Directory with empty `MODULE.bazel` file, `BUILD` file with following content:
```
filegroup(
name = "target",
srcs = [],
)
```

Bazel invocation:
`bazel build target --build_event_binary_file=test.bin --experimental_stream_log_file_uploads=true`

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

Linux, MacOS

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

release 8.4.2

### 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` ?

```text

```

### 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_

Reproduce the failure in a directory containing the empty MODULE.bazel and the shown BUILD file, using the provided Bazel invocation with --build_event_binary_file and --experimental_stream_log_file_uploads=true. Investigate the BEP file-writing and upload path; done means the build completes without the “No available uploader” error and the requested BEP file is written.

Written by the indexing model from the issue text.