add the batch_id to the tasks

crates/meilisearch/tests/snapshot/mod.rs

@@ -151,6 +151,7 @@ async fn perform_on_demand_snapshot() {
     snapshot!(json_string!(task, { ".enqueuedAt" => "[date]", ".startedAt" => "[date]", ".finishedAt" => "[date]", ".duration" => "[duration]" }), @r###"
     {
       "uid": 4,
+      "batchUid": 4,
       "indexUid": null,
       "status": "succeeded",
       "type": "snapshotCreation",