fix(response_cache): returns error when you have an error invalidating data

.changesets/fix_bnjjj_fix_invalidation_error.md

@@ -0,0 +1,5 @@
+### Response cache: returns error when you have an error invalidating data ([PR #8813](https://github.com/apollographql/router/pull/8813))
+
+Without this fix it will never throw an error. Once you deploy this change you might see some increase in `apollo.router.operations.response_cache.invalidation.error` metric.
+
+By [@bnjjj](https://github.com/bnjjj) in https://github.com/apollographql/router/pull/8813

apollo-router/src/plugins/response_cache/storage/redis.rs

@@ -453,7 +453,7 @@ impl CacheStorage for Storage {
         let mut counts = HashMap::with_capacity(num_subgraphs);
         while let Some(result) = join_set.join_next().await {
             let (subgraph_name, count) = result?;
-            counts.insert(subgraph_name, count.unwrap_or(0));
+            counts.insert(subgraph_name, count?);
         }
 
         Ok(counts)