Enable new Axum implementation for the HTTP tracker

[josecelano]

Parent issue: #160

We have finished the migration to Axum, but the setup.rs in the production code still runs the Warp version:

// Start the HTTP blocks
for http_tracker_config in &config.http_trackers {
    if !http_tracker_config.enabled {
        continue;
    }
    jobs.push(http_tracker::start_job(http_tracker_config, tracker.clone(), Version::Warp).await);
}

This issue enables the new Axum implementation:

// Start the HTTP blocks
for http_tracker_config in &config.http_trackers {
    if !http_tracker_config.enabled {
        continue;
    }
    jobs.push(http_tracker::start_job(http_tracker_config, tracker.clone(), Version::Axum).await);
}

After merging this change, the new Axum implementation will be used when you run the HTTP tracker.