qe: always create a span for prisma:engine regardless of iTX

Prevent `prisma:engine:response_json_serialization` span from being
orphan when using interactive transactions.

This check made sense in the past in principle when there were no child
spans outside of the iTX runner, and the `prisma:engine` span didn't
cover the whole `Engine::query` method duration, but now it makes more
sense to always create it.

Fixes: prisma/prisma#21402

query-engine/query-engine-node-api/src/engine.rs

@@ -19,7 +19,7 @@ use serde::Deserialize;
 use serde_json::json;
 use std::{collections::HashMap, future::Future, marker::PhantomData, panic::AssertUnwindSafe, sync::Arc};
 use tokio::sync::RwLock;
-use tracing::{field, instrument::WithSubscriber, Instrument, Span};
+use tracing::{field, instrument::WithSubscriber, Instrument};
 use tracing_subscriber::filter::LevelFilter;
 use user_facing_errors::Error;
 
@@ -314,12 +314,7 @@ impl QueryEngine {
 
             let query = RequestBody::try_from_str(&body, engine.engine_protocol())?;
 
-            let span = if tx_id.is_none() {
-                tracing::info_span!("prisma:engine", user_facing = true)
-            } else {
-                Span::none()
-            };
-
+            let span = tracing::info_span!("prisma:engine", user_facing = true);
             let trace_id = telemetry::helpers::set_parent_context_from_json_str(&span, &trace);
 
             async move {