Transaction is not finished if panic occurs within it

[lcian]

Steps to Reproduce

Run the following example:

use axum::routing;
use axum::{extract::Request, Router};
use tower;

async fn handler() -> String {
    let parent_span = sentry::configure_scope(|scope| scope.get_span());
    if let Some(sentry::TransactionOrSpan::Transaction(tx)) = parent_span {
        let span = tx.start_child("span operation", "span description");
        span.finish();
    }
    panic!("oh no");
}

#[tokio::main]
async fn main() {
    let _guard = sentry::init((
        "https://6b76fb2a5dc1164849cd797b75b6d879@o447951.ingest.us.sentry.io/4508694563782656",
        sentry::ClientOptions {
            release: sentry::release_name!(),
            traces_sample_rate: 1.0,
            debug: true,
            ..Default::default()
        },
    ));

    let app = Router::new().route("/", routing::get(handler)).layer(
        tower::ServiceBuilder::new()
            .layer(sentry_tower::NewSentryLayer::<Request>::new_from_top())
            .layer(sentry_tower::SentryHttpLayer::with_transaction()),
    );

    let listener = tokio::net::TcpListener::bind("0.0.0.0:3000").await.unwrap();
    axum::serve(listener, app).await.unwrap();
}

Expected Result

• The "GET /" transaction and the manually created span are captured
• The trace and transaction are marked as errored, the transaction associated with the issue corresponding to the panic

Example from Python

Actual Result

Only the panic is reported, with a fake trace ("Missing Trace Spans")

[lcian]

Fixed in #727