fix: improve db loads by adding index on audit

backend/windmill-api/src/db.rs

@@ -551,6 +551,7 @@ async fn v2_finalize(db: &DB) -> Result<(), Error> {
         )
         .await?;
     });
+
     Ok(())
 }
 
@@ -768,6 +769,12 @@ async fn fix_job_completed_index(db: &DB) -> Result<(), Error> {
             .execute(db)
             .await?;
     });
+
+    run_windmill_migration!("audit_timestamps", db, |tx| {
+        sqlx::query!("CREATE INDEX CONCURRENTLY ix_audit_timestamps ON audit (timestamp DESC)")
+            .execute(db)
+            .await?;
+    });
     Ok(())
 }