[Feature] Add test helper for tracestorage subscriber

### Component

protocol

### Describe the feature you would like

https://github.com/alloy-rs/op-alloy/blob/2a70833399915b6ee2a0f6418ceee4dc2ff209df/crates/protocol/src/batch/span.rs#L633-L635

this doesn't work in regular cargo test because this uses the global tracing dispatcher and will panic if already configured

### Additional context

_No response_