Reflection: Cannot reflect service that imports from another file: `file ... included an unresolvable reference`

### Problem description
I am not able to use reflection after setting up `@grpc/reflection`. Attempting to reflect any service that imports a message from another file gives an error similar to

```
Error invoking method "hello_world.HelloWorldService/helloWorld": failed to query for service descriptor "hello_world.HelloWorldService": file "hello_world.proto" included an unresolvable reference to ".hello_world.hello_world_service.HelloWorldRequest"
```

### Reproduction steps
Example repo demonstrating the issue: https://github.com/robrichard/grpc-reflection-test
Exact reproduction steps are in the README.md of that repo.

### Environment
- macOs Sequoia 15.6
- Node version v20.11.1
- Package name and version:
- @grpc/grpc-js: 1.14.0,
- @grpc/proto-loader: 0.8.0
- @grpc/reflection: 1.0.4