Continue processing Stripe events after seeing one that's > 1 day old (#30971)

This mostly affects local development. It fixes a bug where we would
only process one Stripe event per polling period (5 seconds) when
hitting old events.

Release Notes:

- N/A

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/collab/src/api/billing.rs

@@ -971,7 +971,7 @@ async fn poll_stripe_events(
                 .create_processed_stripe_event(&processed_event_params)
                 .await?;
 
-            return Ok(());
+            continue;
         }
 
         let process_result = match event.type_ {