Place TODO to refactor BatchSpanProcessor [run ci]

Author: 50U10FCA7

opentelemetry-sdk/src/trace/span_processor_with_async_runtime.rs

@@ -250,6 +250,8 @@ where
                     if !self.export_tasks.is_empty()
                         && self.export_tasks.len() == self.config.max_concurrent_exports
                     {
+                        // TODO: Refactor to avoid stopping message processing to not delay
+                        //       shutdown/resource set because of export saturation.
                         self.export_tasks.next().await;
                     }
 
@@ -307,7 +309,7 @@ where
         true
     }
 
-    fn export(&mut self) -> impl Future<Output = OTelSdkResult> + use<E, R> {
+    fn export(&mut self) -> impl Future<Output = OTelSdkResult> {
         let spans = self.spans.drain(..).collect::<Vec<_>>();
         let exporter = self.exporter.clone();
         let runtime = self.runtime.clone();